The ACh-stimulated increase in [Ca2+]i in bovine adrenal chromaffin cells is mainly triggered by an influx of Ca2+ through the nAChR channel, VOC, and the subsequent activation of Ca2+-induced Ca2+ release, all of which contribute to CA release. These events in response to ACh are of short duration, whereas PACAP induces large and sustained increases in [Ca2+]i and CA release. The present study sought to elucidate which pathways (nAChR channel, VOC, SOC, or an unidentified channel) contribute to this peculiar Ca2+ and secretory response to PACAP.. Reports vary concerning the effect of VOC blockers on PACAP-induced rise in [Ca2+]i and CA release. For example, Przywara et al. (1996) showed that in rat cultured adrenal chromaffin cells, neither L- nor N-type VOC participates in the PACAP-induced CA release. On the other hand,Fukushima et al. (2001b) showed that nifedipine, L-type VOC antagonist, reduced PACAP-induced CA release in isolated perfused rat adrenal gland. Tanaka et al. (1996) reported ...
Fingerprint Dive into the research topics of Proenkephalin processing enzyme with specificity toward paired basic residues purified from bovine adrenal chromaffin granules. Together they form a unique fingerprint. ...
Bovine chromaffin-granule ghosts accumulate 45Ca2+ in a temperature- and osmotic-shock-sensitive process; the uptake is saturable, with Km 38 microM and Vmax. 28 nmol/min per mg at 37 degrees C. Entry occurs by exchange with Ca2+ bound to the inner surface of the membrane. It is inhibited non-competitively by Na+, La3+ and Ruthenium Red (Ki 10.7 mM, 7 microM and 2 microM respectively), and competitively by Mg2+ (ki 0.9 mM). Uptake was not stimulated by ATP. Na+ induces Ca2+ efflux; Ca2+ can re-enter the ghosts by a process of Ca2+/Na+ exchange. La3+ inhibits Ca2+ efflux during Ca2+-exchange, and Ca2+ efflux induced by Na+, suggesting that Ca2+ uptake and efflux, and Ca2+/Na+ exchange, are catalysed by the same protein. Na+ enters ghosts during CA2+ efflux, but the kinetics of its entry are not exactly similar to the kinetics of Ca2+ efflux. Initially 1-2 Na+ enter per Ca2+ lost, but at equilibrium 3-4 Na+ have replaced each Ca2+. There is no evidence that either Ca2+ uptake or efflux by Ca2+/Na+ ...
Dopamine-ß-hydroxylase (DßH), an enzyme which catalyzes the conversion of dopamine to norepinephrine, is the only enzyme of the catecholamine biosynthetic pathway located in the chromaffin granules of adrenal medulla. Within the granules, two populations of DßH exist: a water-soluble fraction found within the granule matrix and a membrane-bound, amphiphilic fraction embedded in the surrounding bilayer. The amphiphilic form was purified to homogeneity following its extraction from the membrane with the non-ionic detergent BRIJ 58. Three steps were required to achieve complete purification: adsorption to ConA-Sepharose, adsorption to DEAE Sephadex A-25, and chromatography on Sephacryl S-200, Sepharose 6B, or Sepharose CL-4B. The presence of 0.1-0.2 mg/ml BRIJ 58 was essential for protein recovery. The enzymatic and structural characteristics of membrane-bound DßH were found to be similar to those of soluble DßH. Initial velocity data indicated a Ping-pong or double-displacement reaction with ...
Membranes of chromaffin granules were isolated from the adrenal glands of four different species. The solubilized membrane proteins could be resolved into several bands by polyacrylamide-gel electrophoresis (alkaline and acid gel systems). Two major protein components appeared to be common to the chromaffin granule membranes of ox, horse, pig and man. The various membrane proteins of bovine chromaffin granules were separated by filtration on Sephadex G-200 in the presence of sodium dodecyl sulphate. Two major membrane proteins (A and B) were obtained in purified form. Treatment of protein A with 2-mercaptoethanol before electrophoresis resulted in two more rapidly migrating subunits, whereas protein B was unaffected by mercaptoethanol treatment. The amino acid compositions of the two purified proteins were determined. They are very similar to that of the total membrane proteins but significantly different from that of the chromogranins, the soluble proteins of chromaffin granules.. ...
In a previous report, we described the ability of two secretogogues, histamine and nicotine, to stimulate additive effects on catecholamine (CA) release and synapsin II phosphorylation in bovine adrenal chromaffin cells (BACC) [Firestone and Browning (1992), J. Neurochem., 58:441-447]. We hypothesized that these results were due to the combined effects on cytosolic Ca++ of the two distinct signalling pathways. We therefore examined the intracellular Ca++ signals stimulated by histamine and nicotine, alone and together. In Ca(++)-deficient medium, nicotine-stimulated signals were abolished, whereas histamine-stimulated signals were maintained, demonstrating that nicotine depended entirely on Ca++ influx for its effects. Indeed, the nicotine-stimulated signal could also be prevented using a Ca++ channel blocker, nicardipine. Further, the observation that exposure of BACC to thapsigargin reduced histamine-stimulated Ca++ signals verified that histamine mobilizes Ca++ from intracellular stores. Thus, the
Investigations into the effects of culturing bovine adrenal chromaffin cells in the presence (72 h) of dibutyryl cyclic AMP, forskolin, and reserpine on the level and release of [Met]enkephalyl-Arg6-Phe7 immunoreactivity, noradrenaline, and adrenaline are reported. The assay for [Met]enkephalyl-Arg6-Phe7 immunoreactivity recognises both peptide B, the 31-amino acid carboxy-terminal segment of proenkephalin, and its heptapeptide fragment, [Met]enkephalyl-Arg6-Phe7. Treatments that elevate cyclic AMP increase the amount of peptide immunoreactivity in these cells; this is predominantly peptide B-like immunoreactivity in both control cells and cyclic AMP-elevated cells. Treatment with reserpine gives no change in total immunoreactivity levels, but does not result in increased accumulation of the heptapeptide [Met]enkephalyl-Arg6-Phe7 at the expense of immunoreactivity that elutes with its immediate precursor, peptide B. Cyclic AMP treatment causes either no change or a decrease in levels of accumulated
TY - JOUR. T1 - Molecular cloning of cDNA encoding the C subunit of H+-ATPase from bovine chromaffin granules. AU - Nelson, H.. AU - Mandiyan, S.. AU - Noumi, T.. AU - Morihama, Y.. AU - Miedel, M. C.. AU - Nelson, N.. PY - 1990/12/18. Y1 - 1990/12/18. N2 - A cDNA encoding subunit C of the V-ATPase from bovine chromaffin granules was cloned and sequenced. The gene encodes a hydrophilic protein of 382 amino acids with a calculated molecular weight of 43,989. Hydropathy plots revealed no apparent transmembrane segments and a rather high helix content was detected. A cDNA encoding most of the C subunit of the V-ATPase of human brain was also cloned and sequenced. The deduced amino acid sequence of this gene is almost identical to the bovine polypeptide with only one change of tyrosine 336 that was replaced by histidine in the human gene. Two polypeptide fragments derived from subunit E of V-ATPase from chromaffin granules were sequenced and found to be identical to the predicted amino acid sequence ...
Rat pheochromocytoma cells (PC 12) permeabilized with staphylococcal α-toxin release [3H]dopamine after addition of micromolar Ca2+. This does not require additional Mg2+-ATP (in contrast to bovine adrenal medullary chromaffin cells). We also observed Ca2+-dependent [3H]-dopamine release from digitonin-permeabilized PC 12 cells. Permeabilization with α-toxin or digitonin and stimulation of the cells were done consecutively to wash out endogenous Mg2+-ATP. During permeabilization, ATP was removed effectively from the cytoplasm by both agents but the cells released [3H]dopamine in response to micromolar Ca2+ alone. Replacement by chloride of glutamate, which could sustain mitochondrial ATP production in permeabilized cells, does not significantly alter catecholamine release induced by Ca2+. However, Mg2+ without ATP augments the Ca2+-induced release. The release was unaltered by thiol-, hydroxyl-, or calmodulin-interfering substances. Thus Mg2+-ATP, calmodulin, or proteins containing -SH or -OH ...
Adrenal chromaffin cells (ACCs) secrete several neuroactive substances that are effective in influencing pain sensitivity in the central nervous system as well as enhancing the recovery of the intrinsic nigrostriatal dopaminergic system in patients w
TY - JOUR. T1 - Sodium-azide-evoked noradrenaline and catecholamine release from peripheral sympathetic nerves and chromaffin cells. AU - Török, Tamás L.. AU - Pauló, Tünde. AU - Tóth, Péter T.. AU - Azzidani, Awad M.. AU - Powis, David A.. AU - Magyar, K.. PY - 1989. Y1 - 1989. N2 - 1. 1. The spontaneous release of [3H]noradrenaline ([3H]NA) has been measured from rabbit pulmonary arteries and bovine chromaffin cells in the presence of neuronal uptake blocker cocaine (3 × 10-5 M). 2. 2. The Na+-pump inhibitor sodium-azide (NaN3, 2 mM) produced a moderate increase of [3H]NA release from both preparations and relaxed the arteries. The [3H]releasing action of NaN3 was accompanied by a 30% inhibition of 86Rb-uptake into chromaffin cells. 3. 3. In both preparations, ouabain (10-4 M) markedly increased the release of [3H], contracted the arteries and inhibited the 86Rb-uptake of chromaffin cells by about 75%. A combined application of NaN3 and ouabain produced a similar inhibition of ...
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Catecholamine secretion in the bovine adrenal medulla is evoked largely by nicotinic receptor activation. However, bovine adrenal medulla also contain muscarini
Author: Nili, U. et al.; Genre: Journal Article; Published in Print: 2006-12-01; Title: Munc18-1 phosphorylation by protein kinase C potentiates vesicle pool replenishment in bovine chromaffin cells
Other articles where Chromaffin cell is discussed: human nervous system: The endocrine system: Within the adrenal medulla are chromaffin cells, which are homologous to sympathetic neurons and, like sympathetic neurons, are developed from embryonic neural crest cells. Chromaffin cells produce epinephrine (adrenaline) and, to a much lesser extent, norepinephrine as well as other chemicals such as chromogranins, enkephalins, and neuropeptide Y-all of which…
Buy BAM (8-22) (Bovine Adrenal Medulla 8-22) (CAS 412961-36-5), a water soluble SNSR agonist. Join researchers using high quality BAM (8-22) (Bovine Adrenal…
The properties of Ca(2+)- and voltage-dependent K+ currents and their role in defining membrane potential were studied in cultured rat chromaffin cells. Two variants of large-conductance, Ca2+ and voltage-dependent BK channels, one noninactivating and one inactivating, were largely segregated among patches. Whole-cell noninactivating and inactivating currents resulting from each of these channels were segregated among different chromaffin cells. Cell-to-cell variation in the rate and extent of whole-cell current decay was not explained by differences in cytosolic [Ca2+] regulation among cells; rather, variation was due to differences in the intrinsic properties of the underlying BK channels. About 75% of rat chromaffin cells and patches express inactivating BK current (termed BKi) while the remainder express noninactivating BK current (termed BKs). The activation time course of both currents is similar, as is the dependence of activation on [Ca2+] and membrane potential. However, deactivation of ...
Nili, U.; de Wit, H.; Gulyas-Kovacs, A.; Toonen, R. F.; Soerensen, J. B.; Verhage, M.; Ashery, U.: Munc18-1 phosphorylation by protein kinase C potentiates vesicle pool replenishment in bovine chromaffin cells. Neuroscience 143 (2), pp. 487 - 500 (2006 ...
Adrenal medullary chromaffin cell culture systems are extremely useful for the study of excitation-secretion coupling in an in vitro...
Treatment of cultured bovine adrenal chromaffin cells with the catecholamine transport blocker reserpine was previously shown to increase enkephalin levels several-fold. To explore the biochemical mechanism of this effect, we examined the effect of reserpine treatment on the activities of three different peptide precursor processing enzymes: carboxypeptidase E (CPE) and the prohormone convertases (PCs) PC1/3 and PC2. Reserpine treatment increased both CPE and PC activity in extracts of cultured chromaffin cells; total protein levels were unaltered for any enzyme. Further analysis showed that the increase in CPE activity was due to an elevated Vmax, with no change in the Km for substrate hydrolysis or the levels of CPE mRNA. Reserpine activation of endogenous processing enzymes was also observed in extracts prepared from PC12 cells stably expressing PC1/3 or PC2. In vitro experiments using purified enzymes showed that catecholamines inhibited CPE, PC1/3 and PC2, with dopamine quinone the most ...
TY - JOUR. T1 - Recapture after exocytosis causes differential retention of protein in granules of bovine chromaffin cells. AU - Perrais, David. AU - Kleppe, Ingo C.. AU - Taraska, Justin W.. AU - Almers, Wolfhard. PY - 2004/10/15. Y1 - 2004/10/15. N2 - After exocytosis, chromaffin granules release essentially all their catecholamines in small fractions of a second, but it is unknown how fast they release stored peptides and proteins. Here we compare the exocytic release of fluorescently labelled neuropeptide Y (NPY) and tissue plasminogen activator from single granules. Exocytosis was tracked by measuring the membrane capacitance, and single granules in live cells were imaged by evanescent field microscopy. Neuropeptide Y left most granules in small fractions of a second, while tissue plasminogen activator remained in open granules for minutes. Taking advantage of the dependence on pH of the fluorescence of green fluorescent protein, we used rhythmic external acidification to determine whether ...
Cleavage of the disulfide bond linking the heavy and the light chains of tetanus toxin is necessary for its inhibitory action on exocytotic release ofcatecholamines from permeabi1ized chromaffin cells [(1989) FEBS Lett. 242, 245-248; (1989) J. Neurochern., in press]. The related botulinum A toxin also consists of a heavy and a light chain linked by a disulfide bond. The actions ofboth neurotoxins on exocytosis were presently compared using streptolysin O-permeabilized bovine adrenal chromaffin cells. Botulinum A toxin inhibited Ca2 +-stimulated catecholamine release from these cells. Addition of dithiothreitollowered the effective doses to values below 5 nM. Under the same conditions, the effective doses of tetanus toxin were decreased by a factor of five. This indicates that the interchain S-S bond of botulinum A toxin must also be split before the neurotoxin can exert its effect on exocytosis. ...
The previous sections describe the different exocytotic responses obtained when the amount of Ca2+ entry is altered at a constant interpulse interval (200 msec). To examine whether the exocytotic response of a cell is also influenced by the time span between bouts of Ca2+ entry, we tested various interpulse intervals.. Trains of 40 msec pulses at 200 msec intervals evoked depressed responses in most cells (Figs. 3C, 4). Prolonging the interpulse interval increased the Ca2+ efficacy without significant changes to total Ca2+ entry (Fig. 8). Three examples comparing a 200 and a 1000 msec interval stimulus train within individual cells are shown in Figure 8A. Cells with strong depression during the 200 msec train showed a partial relief of depression at 1000 msec intervals (Fig. 8A,i) or followed the standard curve (Fig. 8A,ii), whereas cells with less depression often gave large responses with enhanced Ca2+ efficacy (Fig. 8A,iii). A summary of 17 experiments is presented in Figure 8B, in which the ...
Large-conductance Ca2+- and voltage-dependent potassium (BK) channels exhibit functional diversity not explained by known splice variants of the single Slo α-subunit. Here we describe an accessory subunit (β3) with homology to other β-subunits of BK channels that confers inactivation when it is coexpressed with Slo. Message encoding the β3 subunit is found in rat insulinoma tumor (RINm5f) cells and adrenal chromaffin cells, both of which express inactivating BK channels. Channels resulting from coexpression of Slo α and β3 subunits exhibit properties characteristic of native inactivating BK channels. Inactivation involves multiple cytosolic, trypsin-sensitive domains. The time constant of inactivation reaches a limiting value ∼25-30 msec at Ca2+ of 10 μm and positive activation potentials. Unlike Shaker N-terminal inactivation, but like native inactivating BK channels, a cytosolic channel blocker does not compete with the native inactivation process. Finally, the β3 subunit confers a ...
Atrial natriuretic peptide is stored by atrial myocytes in secretory granules, known as atrial specific granules, and is released from these granules by exocytosis. We have isolated a group of atrial proteins by affinity chromatography that bind to atrial specific granules in a calcium-dependent manner. The two major proteins isolated (32.5 kd and 67 kd) are calcium-binding proteins and have been identified as annexins V and VI by immunoblotting with specific antisera. The calcium dependence of their binding to atrial specific granules has been characterized in vitro and indicates that this interaction takes place at micromolar levels of calcium. In addition, the group of proteins isolated includes another calcium-binding protein of 20 kd, as well as GTP-binding proteins of 22 to 26 kd. Membrane interactions during exocytosis are presumably mediated by the interaction of specific proteins with the granule membrane. The properties of the proteins described here, and their ability to bind to ...
Synaptotagmin-1 and -7 constitute the main calcium sensors mediating SNARE-dependent exocytosis in mouse chromaffin cells, but the role of a closely related calcium-binding protein, Doc2b, remains enigmatic. We investigated its role in chromaffin cells using Doc2b knock-out mice and high temporal resolution measurements of exocytosis. We found that the calcium dependence of vesicle priming and release triggering remained unchanged, ruling out an obligatory role for Doc2b in those processes. However, in the absence of Doc2b, release was shifted from the readily releasable pool to the subsequent sustained component. Conversely, upon overexpression of Doc2b, the sustained component was largely inhibited whereas the readily releasable pool was augmented. Electron microscopy revealed an increase in the total number of vesicles upon Doc2b overexpression, ruling out vesicle depletion as the cause for the reduced sustained component. Further experiments showed that, in the absence of Doc2b, the ...
RT-PCR and Western blotting techniques established the expression of APC protein both in bovine adrenal chromaffin cells, which express native alpha 3 beta 4* nAChRs, and in a HEK293 cell line expressing recombinant bovine adrenal alpha 3 beta 4 nAChRs (BM alpha 3 beta 4 cells). Transfection of BM alpha 3 beta 4 cells with siRNA to APC, reduced APC protein. levels to 52.4% and 61.9% of control values at 24 and 48 h after transfection. To investigate the effects of APC on the cellular distribution of alpha 3 beta 4 nAChRs, [(3)H]epibatidine binding approaches, coupled with APC siRNA treatment, were used. Twenty-four and 48 h after APC siRNA transfection, intracellular nAChRs were significantly reduced to 71% and 68% of control, respectively, while the total population of nAChRs were. not significantly changed. Given that total cellular nAChRs represent IKK inhibitor the sum of surface and intracellular nAChRs, these studies support a re-distribution of nAChRs to the plasma membrane with APC siRNA ...
In addition to the canonical ribonucleoside and deoxyribonucleoside phosphates and cofactors, cells contain a large number of minor nucleotides. Among these are the diadenosine polyphosphates (ApnA, where n = 2-7 [1]). Ap3A and Ap4A are the most intensively studied of these and are generally present in the soluble fraction of eukaryotic and prokaryotic cells at concentrations between 10 nM and 5 μM [2]. Platelet dense granules, adrenal chromaffin granules and certain synaptic vesicles have been reported to contain high concentrations of Ap5A and Ap6A in addition to Ap3A and Ap4A, all of which can be exocytosed following appropriate stimuli and bind to target cell purinoceptors causing a variety of physiological responses in the cardiovascular and central and peripheral nervous systems [1, 3-5]. However, although Ap6A has been detected in erythrocytes [6], there are no substantiated measurements of Ap5A and Ap6A in the soluble fraction of nucleated cells, and it is likely that they are typically ...
Chromaffin cells are neuroendocrine cells found predominantly in the medulla of the adrenal gland. They are also found in other ganglia of the sympathetic nervous system and are derived from the embryonic neural crest. Embryology They arise in ...
Area of interest: Mechanisms of stress transduction at the sympatho-adrenal synapse; optical studies of hormone trafficking and secretion in the adrenomedullary chromaffin cell.
The role of nongenomic action of estrogens on elicited catecholamine secretion and exocytosis kinetics was studied in perfused rat adrenals and in cultured bovine chromaffin cells. 17β-Estradiol as well as the estrogen receptor modulators raloxifene and LY117018, but not 17α-estradiol, inhibited at the micromolar range the catecholamine output elicited by acetylcholine or high potassium. However, these agents failed to modify the secretion elicited by high Ca2+ in glands treated with the ionophore A-23187 (calcimycin), suggesting that estrogens did not directly act on the secretory machinery. At the single cell level, estrogens modified the kinetics of exocytosis at nanomolar range. All of the drugs tested except 17α-estradiol produced a profound slowing down of the exocytosis as measured by amperometry. LY117018 also reduced the granule content of catecholamines. 17β-Estradiol reduced the intracellular free Ca2+ but only at micromolar concentrations, whereas nanomolar concentrations ...
Cultures of bovine adrenomedullary chromaffin cells accumulated 1-methyl-4-phenylpyridinium (MPP+) in a time- and concentration-dependent manner by a process that was prevented by desmethylimipramine. The subcellular localization of the incorporated [methyl-3H]MPP+ was examined by differential centrifugation and sucrose density gradient fractionation and was found to be predominantly colocalized with catecholamines in chromaffin vesicles, and negligible amounts were detected within the mitochondrial fraction. When chromaffin cell membranes were made permeable with the detergent digitonin in the absence of calcium, there was no increase in the release of [3H]MPP+, indicating that there is negligible accumulation of the neurotoxin in the cytosol. Simultaneous exposure to digitonin and calcium induced cosecretion of MPP+ and catecholamines. Stimulation of the cells with nicotine released both catecholamines and MPP+ at identical rates and percentages of cellular content in a calcium-dependent ...
TY - JOUR. T1 - Differential subcellular distribution of PC1, PC2 and furin in bovine adrenal medulla and secretion of PC1 and PC2 from this tissue. AU - Kirchmair, R.. AU - Egger, C.. AU - Gee, P.. AU - Hogue-Angeletti, R.. AU - Fischer-Colbrie, R.. AU - Laslop, A.. AU - Winkler, H.. N1 - Funding Information: This work was supported by the Fonds zur F6rderung ,ter wissenschaftlichen Forschung (Austria), by the Dr. Legerlotz-Stiftung and by funds from NIH (Grant NS 22697, R.H.-A.). PY - 1992/8/31. Y1 - 1992/8/31. N2 - The subcellular distribution of PC1, PC2 and furin was determined in bovine adrenal medulla by immunoblotting of fractions obtained by density gradient centrifugation. PC1 and PC2 were found to be confined to chromaffin granules whereas furin (C-terminal-peptide) was absent from these organelles. Stimulation of bovine adrenal medulla by carbamoylcholine chloride induced the secretion of PC1 and PC2. The secreted enzymes had the same molecular size as PC1 and PC2 present in ...
Synaptotagmin-1, the canonical isoform of the synaptotagmin family, is a Ca(2+) sensor for fast synchronous neurotransmitter release in forebrain neurons and chromaffin cells. Even though deletion of synaptotagmin-1 abolishes fast exocytosis in chromaffin cells, it reduces overall secretion by only 20% because of the persistence of slow exocytosis. Therefore, another Ca(2+) sensor dominates release in these cells. Synaptotagmin-7 has a higher Ca(2+) affinity and slower binding kinetics than synaptotagmin-1, matching the proposed properties for the second, slower Ca(2+) sensor. Here, we examined Ca(2+)-triggered exocytosis in chromaffin cells from KO mice lacking synaptotagmin-7, and from knockin mice containing normal levels of a mutant synaptotagmin-7 whose C(2)B domain does not bind Ca(2+). In both types of mutant chromaffin cells, Ca(2+)-triggered exocytosis was decreased dramatically. Moreover, in chromaffin cells lacking both synaptotagmin-1 and -7, only a very slow release component, ...
TY - JOUR. T1 - Cell-free translation of enkephalin-precursor messenger RNA from bovine adrenal medulla and corpus striatum.. AU - Sabol, S. L.. AU - Dandekar, Satya. AU - Kranzler, L. S.. PY - 1982. Y1 - 1982. UR - http://www.scopus.com/inward/record.url?scp=0020021542&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=0020021542&partnerID=8YFLogxK. M3 - Article. C2 - 7124494. AN - SCOPUS:0020021542. VL - 33. SP - 175. EP - 181. JO - Advances in biochemical psychopharmacology. JF - Advances in biochemical psychopharmacology. SN - 0065-2229. ER - ...
Since the work of Katz, Douglas, and their collaborators almost half a century ago (Katz, 1969), a central concept in the physiology of neurosecretion is that a rise in cytosolic [Ca2+], resulting from Ca2+ influx, triggers exocytosis. More recently it has become clear that the rise in [Ca2+] occurs in a microdomain within the vicinity (i.e., at a distance of 200-300 nm in chromaffin cells) of plasmalemmal Ca2+ channels (García et al., 2006; Neher and Sakaba, 2008). This finding raises the possibility of other microdomains where a rise in focal [Ca2+] might mediate other processes, allowing Ca2+ to subserve several functions without cross talk. This possibility receives further support from the study of Ca2+ sparks in smooth muscle cells. Ca2+ sparks are focal Ca2+ transients found in striated and smooth muscle and mediated by RYRs (Cheng and Lederer, 2008). In striated muscle, they are the quanta or building blocks that make up a global increase in [Ca2+] to trigger contraction (Csernoch, ...
Start Over You searched for: Authors International Symposium on Chromaffin Cell Biology 1986 : Coolfont, W. Va.) ✖Remove constraint Authors: International Symposium on Chromaffin Cell Biology 1986 : Coolfont, W. Va.) Languages English ✖Remove constraint Languages: English Subjects Cellular Structures ✖Remove constraint Subjects: Cellular Structures ...
Adrenal chromaffin cells are excitable neuroendocrine cells that have been widely used as a simple model of neurosecretion. In vivo, acetylcholine released from preganglionic neurons binds to nicotinic receptors, which are Na+ ionophores, causing Na+ influx that depolarizes the plasma membrane. Depolarization in turn causes voltage-gated calcium channels (VGCCs) to open, leading to an influx of Ca2+ that activates the fusion of secretory granules with the plasma membrane, resulting in catecholamine release that occurs within milliseconds. This Ca2+-dependent secretory process is referred to as exocytosis. Previous investigations exploring the potential for nanosecond electric pulses (NEPs) to serve as a novel bioelectric stimulus of neurosecretion in chromaffin cells have shown that in chromaffin cells exposed to 5 ns, 5 MV/m electric pulses, catecholamine release is stimulated in a manner that relies on Ca2+ influx via VGCCs. The goal of the present study was to further understand this novel ...
The sympathetic nervous system is activated by a variety of threats to organismal homeostasis. The adrenomedullary chromaffin cell is the core effector of sympathetic activity in the peripheral nervous system. By design, the chromaffin cell secretory response is mutable so that release can be rapidly tuned to drive context-dependent changes in physiological function. However, the mechanisms by which this tuning is achieved with such high temporal fidelity and context specificity remain unclear. This represents a major gap in our understanding of the sympatho-adrenal system since it is known to modify the function of nearly every organ system in the body. In chromaffin cells, the trigger for stimulus-evoked exocytosis is a rise in intracellular Ca2+. The level of intracellular Ca2+ accumulation varies with the stimulus intensity and secretagogue. Ca2+ regulates release by acting on the Ca2+-binding synaptotagmin (Syt) protein family, driving their penetration into membranes that harbor anionic lipids,
With the type of cryofixation we used (sandwich freezing), cells remain permanently surrounded by their culture or trigger medium, and impairment of viability during handling can be minimized (Pscheid et al., 1981). The propane jet applied onto the thin copper cover provides very rapid cooling, i.e., up to 40,000°C·s−1 (Knoll et al., 1982; Plattner and Knoll, 1984). The freeze-substitution medium used includes OsO4 and, thus, precludes osmotic changes during warming (Van Harreveld et al., 1965; Morel et al., 1971; Wollweber et al., 1981), and the epoxide embedding chosen involves little shrinkage (Plattner and Zingsheim, 1983). In other studies, open samples were used for freezing on cold metal surfaces or injection into cold media (Ornberg et al., 1995; Parsons et al., 1995). This requires removal of the culture/trigger medium since cryopreservation is restricted to ∼20 μm (Plattner and Bachmann, 1982). The fluid film that may remain on the sample is very thin and ionic conditions are ...
TY - CHAP. T1 - Adrenomedullin. AU - Abel, Peter. AU - Rorabaugh, Boyd. PY - 2007/1/1. Y1 - 2007/1/1. N2 - Adrenomedullin is a member of the calcitonin family of peptides. It is produced by vascular smooth muscle cells, vascular endothelial cells, cardiomyocytes, adrenal chromaffin cells, macrophages, bronchial epithelium, and many other cell types. This peptide is a potent vasodilator in most vascular beds and has been implicated in the regulation of blood pressure, ..... AB - Adrenomedullin is a member of the calcitonin family of peptides. It is produced by vascular smooth muscle cells, vascular endothelial cells, cardiomyocytes, adrenal chromaffin cells, macrophages, bronchial epithelium, and many other cell types. This peptide is a potent vasodilator in most vascular beds and has been implicated in the regulation of blood pressure, ..... UR - http://www.scopus.com/inward/record.url?scp=84884021496&partnerID=8YFLogxK. UR - ...
The differentiation of neuronal cell progenitors depends on complex interactions between intrinsic cellular programs and environmental cues. Such interactions have recently been explored using an immortalized sympathoadrenal progenitor cell line, MAH. These studies have revealed that depolarizing conditions, in combination with exposure to FGF, can induce responsiveness to NGF. Here we report that CNTF, which utilizes an intracellular signaling pathway distinct from that of both FGF and NGF, can collaborate with FGF to promote efficiently the differentiation of MAH progenitor cells to a stage remarkably reminiscent of NGF-dependent, postmitotic sympathetic neurons. We also find that similar collaborative interactions can occur during transdifferentiation of normal cultured chromaffin cells into sympathetic neurons ...
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Pheochromocytomas are neoplasms of chromaffin tissue that synthesize catecholamines. Pheochromocytoma is a rare disorder that presents challenges for the anesthesiologist. By some estimates, 25 to 50 percent of hospital deaths of patients with unmana
Health expenditure, private (% of GDP) in South Africa was reported at 4.5537 % in 2014, according to the World Bank collection of development indicators, compiled from officially recognized sources. South Africa - Health expenditure, private (% of GDP) - actual values, historical data, forecasts and projections were sourced from the |a href=https://data.worldbank.org/ target=blank>World Bank|/a> on August of 2020.
Fingerprint Dive into the research topics of The actions of propofol on inhibitory amino acid receptors of bovine adrenomedullary chromaffin cells and rodent central neurones. Together they form a unique fingerprint. ...
Dopamine beta-monooxygenase is shown to catalyze the oxidation of N,N,N,N-tetramethyl-1,4-phenylenediamine (TMPD) to its cation radical in the presence of a regular substrate and molecular oxygen. The enzyme-mediated oxidation of TMPD is stoichiometrically coupled with the hydoxylation of the substrate to the corresponding enzymatic product. TMPD is kinetically well behaved as an alternate electron donor for the enzyme with a potency comparable to that of the most efficient electron donor, ascorbate. Dopamine beta-monooxygenase mediated oxidation of TMPD has been employed to design a convenient and sensitive spectrophotometric assay for the enzyme. The finding that TMPD is a well behaved facile alternate electron donor for dopamine beta-monooxygenase raises some interesting novel questions regarding the specificity and chemistry of the reduction site, which may have important implications on the reduction of active site coppers of the enzyme ...
TY - JOUR. T1 - Neuropeptide Y inhibition of nicotinic receptor-mediated chromaffin cell secretion. AU - Hexum, T. D.. AU - Zheng, Jialin C. AU - Zhu, J.. PY - 1994/1/1. Y1 - 1994/1/1. N2 - Neuropeptide Y (NPY), a widely distributed peptide with varied activities, inhibits nicotinic receptor-induced [3H]norepinephrine ([3H]NE) secretion from bovine chromaffin cells. The secretion produced by membrane depolarization with high KCl concentrations or veratridine is not inhibited. Fragments of NPY, such as NPY18-36, are potent inhibitors of [3H]NE secretion, whereas [Leu31,Pro34]-NPY and peptide YY have no effect. The response to NPY18-36 is not sensitive to pertussis toxin pretreatment of chromaffin cells. NPY fragments also inhibit nicotinic receptor-induced 45Ca++ influx but not that induced by KCl or veratridine. The rank orders of potency for inhibition of [3H]NE secretion and 45Ca++ influx are the same: NPY18-36 ≥ NPY26-36 , NPY13-36. NPY and NPY(free acid) are weak inhibitors of secretion ...
TY - JOUR. T1 - Neurosecretory cell-based biosensor. T2 - Monitoring secretion of adrenal chromaffin cells by local extracellular acidification using light-addressable potentiometric sensor. AU - Liu, Qingjun. AU - Hu, Ning. AU - Zhang, Fenni. AU - Wang, Hua. AU - Ye, Weiwei. AU - Wang, Ping. N1 - Funding Information: This work was supported by the National Natural Science Foundation of China (Grant no. 81071226 , 60725102 ), the Research on Public Welfare Technology Application Projects of Zhejiang Province, China (no. 2011C23096 ), the Zhejiang Provincial Natural Science Foundation of China (no. Y2100684 ), and the Fundamental Research Funds for the Central Universities .. PY - 2012/5/15. Y1 - 2012/5/15. N2 - Vesicular exocytosis plays an important role in many physiological processes. The dense-core vesicles release of chromaffi{ligature}n cells is a suitable model for the presynaptic process in neurosecretory cells. In this study, light-addressable potentiometric sensor (LAPS) was introduced ...
S. Karanth, W. H. Yu, A. Walczewska, C. Mastronardi, S. M. McCann, Ascorbic acid acts as an inhibitory transmitter in the hypothalamus to inhibit stimulated luteinizing hormone-releasing hormone release by scavenging nitric oxide, Proceedings of the National Academy of Sciences, 2000, 97, 4, ...
Marley, PD, McLeod, J, Anderson, C and Thompson, KA 1995, Nerves containing nitric oxide synthase and their possible function in the control of catecholamine secretion in the bovine adrenal medulla, Journal of the Autonomic Nervous System, vol. 54, no. 3, pp. 184-194, doi: 10.1016/0165-1838(95)00013-N. ...
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Bovine adrenal medullary slices were incubated at 30° in Lockes solution containing orthophosphate-32P or glycerol-1-14C. 32P was incorporated into all individual phospholipids, but at different rates. The highest specific activity observed was in phosphatidylinositol, followed by phosphatidic acid, phosphatidylcholine, phosphatidylserine, lysophosphatidylcholine (lysolecithin), sphingomyelin, and phosphatidylethanolamine.. Acetylcholine (10-5 M)in the presence of eserine (10-5 M) produced a 3-fold increase in catecholamine release and stimulated the incorporation of 32P into phosphatidic acid (3.4-fold), phosphatidylinositol (2.7-fold), and phosphatidylcholine (1.4-fold).. The uptake of orthophosphate-32P into the chromaffin tissue, as well as the specific activities and tissue levels of orthophosphate and nucleotides, were not modified upon acetylcholine stimulation.. Glycerol-1-14C was incorporated into all the individual phospholipids, but, in contrast to 32P incorporation, acetylcholine ...
First cultured by Greene and Tischler in 1976, PC-12 cells originated from a pheochromocytoma (neuroendocrine tumor) of the rat adrenal medulla. It was developed as a model cell line and an alternative to adrenal chromaffin primary cell cultures. PC-12 cells are able to differentiate into neuron-like cells in the presence of nerve growth factor or dexamethasone. Due to their differentiation ability and ease of culture, PC-12 cells are used in a variety of research areas ranging from drug efficacy to neurosecretion.. ...
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Doxycycline synthroid. In most instances, the biopsy is taken from the actual tumor. Chlorpromazine was with- drawn and doxycycline synthroid substituted (up to a maximum of 600 mgday). Chronic morphine increases levels synthrodi types I (ACI) and VIII (ACVIII) adenylyl cyclase, PKA catalytic (C) and regulatory type II (RII) subunits, and several phosphoproteins, including CREB and tyrosine hydroxylase (TH), the rate-limiting enzyme in norepinephrine biosynthesis.
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