Because an inherited renal factor may contribute to essential hypertension in humans, the study of family members is attractive. To assess the determinants of renal vascular tone, graded doses of either diltiazem (10-1000 micrograms/min) or acetylcholine (1-100 micrograms/min) were infused into the renal artery in 52 normotensive subjects, 16 with and 36 without a family history of hypertension when they were in balance on either a 10-mEq or 200-mEq sodium intake. Renal blood flow was measured with 133Xe. Restricted sodium intake potentiated renal vascular responses to diltiazem (p less than 0.01), suggesting a role for angiotensin as a determinant. In four subjects with no family history of hypertension on a 200-mEq sodium intake, angiotensin II in subpressor doses (1 ng/kg/min i.v.) induced renal vasoconstriction and enhanced the renal vasodilator action of diltiazem (p less than 0.001). In subjects with a family history of hypertension, the renal vascular response to diltiazem was enhanced (p ...
Earlier studies indicate that G₁ mediates enhanced renovascular responses to Ang II in SHR. The potentiation of Ang II by the G₁ pathway is blocked by pretreatment with pertussis toxin, an inhibitor of G₁. The G₁ pathway is also activated by receptors for PP-fold peptides; NPY, PYY, and PYY₃₋₃₆. Therefore, we hypothesize that in genetically predisposed models of hypertension PP-fold peptides augment renovascular responses to endogenous Ang II. Our study shows that LPNPY, an analogue of NPY selective for the Y₁ receptor, potentiates Ang II responses in SHR, but not WKY, kidneys in vitro. LPNPYfs ability to potentiate Ang II renovascular responses is dependent on the Y₁ receptor and an intact G₁ pathway. The renal expression of Y₁ receptors is similar in SHR versus WKY. Our study also demonstrates that PYY₃₋₃₆, selective for the Y₂ receptor, potentiates renovascular responses to Ang II in SHR, but not WKY, in vitro. PYY₃₋₃₆ is dependent on an intact ...
1. Successive infusions of SQ 20 881 given intra-arterially (i.a.) to the kidney at 0.4 and 0.8 μg min−1 kg−1 for 50 min each did not alter renal blood flow and renal vascular resistance in spite of 40-47% blockade of the angiotensin I (ANG I i.a.)-induced vasoconstrictor response.. 2. SQ 20 881 administered intravenously (i.v., 0.5 mg/kg) after the higher intra-arterial dose did not further decrease the renal response to ANG I (i.a.), but caused an increase in renal blood flow and a decrease in renal vascular resistance.. 3. These results indicate that SQ 20 881 has limited efficacy in blocking the renal response to ANG I (i.a.). Under the conditions of these experiments, the renal vasodilator response to SQ 20 881 appears to be due to inhibition of extrarenal rather than intrarenal converting enzyme. ...
The findings of the present study provide new insight into the magnitude and site of action of the renal vasodilatory effect of dopamine and the resulting renal circulatory effects in patients with HF treated with standard HF therapy, including diuretics, neurohormonal blockers, and vasodilators. The present findings show a marked effect of dopamine on RBF. The increase in this parameter started early and became statistically significant at a dose as low as 2 μg · kg−1 · min−1. RBF continued to rise, achieving its highest value at 10 μg · kg−1 · min−1, which was the maximum dose used in the present study. Although the difference between RBF values at a dose of 2 μg · kg−1 · min−1 and higher doses did not reach statistical significance, this may be due to the limited number of patients included in the study. On an individual basis, the present data also demonstrated a high interpatient variability, with a number of subjects achieving maximum response at doses greater than 1 ...
TY - JOUR. T1 - Model of TGF-proximal tubule interactions in renal autoregulation. AU - Cupples, W. A.. AU - Wexler, Anthony S.. AU - Marsh, Donald J.. PY - 1990. Y1 - 1990. N2 - Previous models, assuming constant reabsorption in the proximal tubule, have shown that tubuloglomerular feedback (TGF) can explain only a fraction of glomerular filtration rate (GFR) and renal blood flow autoregulation. Increased arterial pressure inhibits proximal tubule fluid reabsorption, an effect that should increase the efficacy of TGF because of the resulting increased flow rate in the loop of Henle. Models describing pressure and flow in a glomerulus and a nephron were derived to test this prediction. The models were coupled by a TGF function with tubular flow rate at the end of the proximal tubule (superficial nephron) or at the macula densa (juxtamedullary nephron) as input and with afferent arteriolar resistance as output. In agreement with others, the model predicted that TGF alone could account for about ...
We tested whether mild adiposity alters responsiveness of the kidney to activation of the renal sympathetic nerves. After rabbits were fed a high-fat or control diet for 9 wk, responses to reflex activation of renal sympathetic nerve activity (RSNA) with hypoxia and electrical stimulation of the renal nerves (RNS) were examined under pentobarbital anesthesia. Fat pad mass and body weight were, respectively, 74% and 6% greater in fat-fed rabbits than controls. RNS produced frequency-dependent reductions in renal blood flow, cortical and medullary perfusion, glomerular filtration rate, urine flow, and sodium excretion and increased renal plasma renin activity (PRA) overflow. Responses of sodium excretion and medullary perfusion were significantly enhanced by fat feeding. For example, 1 Hz RNS reduced sodium excretion by 79 ± 4% in fat-fed rabbits and 46 ± 13% in controls. RNS (2 Hz) reduced medullary perfusion by 38 ± 11% in fat-fed rabbits and 9 ± 4% in controls. Hypoxia doubled RSNA, ...
Elevation of glomerular capillary pressure is a major risk factor for hypertensive renal injury. Ang II hypertension impairs autoregulation and eliminates P2X1...
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Were kicking off the first segment of our four-part series celebrating all things menstruation for the month of May. Sexual health, particularly vaginal care related to our periods, is often disregarded or ignored. There remains a widespread lack of access to reproductive health care like abortion and menstrual produc
1. The renal vascular response to intravenously administered dopamine was assessed in normal man by selective renal arteriography and xenon washout. Infusion of 3 μg min−1 kg−1 induced renal vasodilatation with an increase in the cortical component of blood flow. Arterial blood pressure was not influenced and a systemic effect was not demonstrable. Lower doses did not induce a renal response. Increasing dosage raised arterial blood pressure and induced subjective symptoms, but did not result in a further increase in renal blood flow.. 2. Renal vascular resistance increased with increasing age in the normal subjects. A significant inverse relationship was found between the initial vascular resistance and the renal vasodilator response to dopamine. It thus appears that the vascular effects of increasing age (nephrosclerosis) may limit the dilator response to dopamine.. 3. It is concluded that dopamine is an effective renal cortical vasodilator when administered intravenously at doses which ...
TY - JOUR. T1 - Injury of the renal microvascular endothelium alters barrier function after ischemia. AU - Sutton, Timothy A.. AU - Mang, Henry E.. AU - Campos, Silvia B.. AU - Sandoval, Ruben M.. AU - Yoder, Mervin C.. AU - Molitoris, Bruce A.. PY - 2003/8/1. Y1 - 2003/8/1. N2 - The role of renal microvascular endothelial cell injury in the pathophysiology of ischemic acute renal failure (ARF) remains largely unknown. No consistent morphological alterations have been ascribed to the endothelium of the renal microvasculature as a result of ischemia-reperfusion injury. Therefore, the purpose of this study was to examine biochemical markers of endothelial injury and morphological changes in the renal microvascular endothelium in a rodent model of ischemic ARF. Circulating von Willebrand factor (vWF) was measured as a marker of endothelial injury. Twenty-four hours after ischemia, circulating vWF peaked at 124% over baseline values (P = 0.001). The FVB-TIE2/GFP mouse was utilized to localize ...
The effects of indomethacin, an inhibitor of prostaglandin synthesis, on renal blood flow, glomerular filtration rate, urine flow and excretion of sodium and potassium were studied in the anesthetized dog. Indomethacin, 2.5 mg/kg i.v., decreased renal blood flow but increased aortic pressure and calculated renal vascular resistance. Glomerular filtration rate was not influenced by the synthetase inhibitor. Sodium excretion was decreased and para-aminohippurate extraction was increased after administration of indomethacin. Transient decreases in urine flow and potassium excretion were observed; however, both parameters returned to control value 75 minutes after administration of indomethacin. The early decrease in urine flow rate correlated closely with the decrease in sodium excretion. These data suggest that in the anesthetized dog, endogenous prostaglandins may serve to maintain renal blood flow but not glomerular filtration rate. Under the conditions of the present experiments, sodium ...
It is well recognized that prolonged elevations of AVP do not produce sustained hypertension (2). In contrast, chronic administration of a V1AG delivered either systemically or into the renal medullary space of rats does result in a mild and sustained form of hypertension (22). It has been shown in anesthetized rats that both AVP and V1AG effectively reduce renal medullary blood flow (17). If such effects were sustained, one would anticipate that both compounds could produce a sustained elevation of arterial pressure because chronic reductions of blood flow to the medulla result in hypertension (1, 12, 15). We hypothesized therefore that the failure of AVP to produce hypertension could be related to an inability of this endogenous peptide to produce a sustained reduction of medullary blood flow. The results of the present study support this hypothesis and show that chronic reduction of blood flow to the inner medulla was not achieved with continuous administration of AVP but did occur with ...
BACKGROUND AND AIM We have reported a novel relationship involving mechanical stimulation and vasodilation in rodent and human skin, referred to as pressure-induced vasodilation (PIV). It is unknown whether this mechanism exists in kidney and reflects the microcirculation in deep organs. Therefore, we compared the skin and kidney PIV to determine whether their changes were similar. METHODS In anesthetized mice fed a normal salt-diet, laser Doppler flux (LDF) signals were measured when an increase in local pressure was applied to the surface of the head skin with the rate of 2.2Pa/s (1mmHg/min) and to the left kidney with a rate of 4.4Pa/s (2mmHg/min). The mechanism underlying renal PIV was also investigated. The skin and kidney PIV were also compared during salt load (4% NaCl diet). RESULTS The kidney had higher baseline LDF and vascular conductance compared to those of the skin. Pressure application increased the LDF in the kidney as well as in the skin with a comparable maximal magnitude (about 25
Ang II and NO have been assigned major roles as counterbalancing regulatory systems in the kidney. The renin-angiotensin system is stimulated during dietary salt restriction or hypovolemia and coordinates a renal response of vasoconstriction and enhanced tubular fluid reabsorption. In contrast, the l-arginine-NO pathway in the kidney is augmented during salt loading and can buffer vasoconstrictive influences on the renal vessels.10 14 15 However, the details of the interaction between these two systems in the kidney remain incompletely understood. The present study showed that short-term infusions of Ang II into anesthetized rats increase the excretion of NO2 and NO3 and lead to dose-dependent increases in NO action on the renal resistance vessels (as assessed from percent changes in RVR with L-NAME). In contrast, more prolonged infusions of Ang II over 5 days do not increase the excretions of NO2 and NO3 nor the action of NO on the renal resistance vessels. These data indicate that the renal ...
Second part of renal physiology which we will address the physiological control of renal blood flow and glomerular filtration. Hypothesis myogenic and macula densa, sympathetic NS and prostaglandins.
To assess changes in renal blood flow (RBF) in human and experimental sepsis, and to identify determinants of RBF. Using specific search terms we systematically interrogated two electronic reference libraries to identify experimental and human studies of sepsis and septic acute renal failure in which RBF was measured. In the retrieved studies, we assessed the influence of various factors on RBF during sepsis using statistical methods. We found no human studies in which RBF was measured with suitably accurate direct methods. Where it was measured in humans with sepsis, however, RBF was increased compared with normal. Of the 159 animal studies identified, 99 reported decreased RBF and 60 reported unchanged or increased RBF. The size of animal, technique of measurement, duration of measurement, method of induction of sepsis, and fluid administration had no effect on RBF. In contrast, on univariate analysis, state of consciousness of animals (P = 0.005), recovery after surgery (P | 0.001), haemodynamic
Sigma-Aldrich offers abstracts and full-text articles by [Y M Al Suleimani, M Al Zaabi, A Ramkumar, A S Al Mahruqi, M H Tageldin, A Nemmar, B H Ali].
Hypoxanthine plus xanthine oxidase causes profound natriuresis without affecting renal blood flow autoregulation. Background Enhanced superoxide production by xanthine oxidase in ischemia/reperfusion has been implicated in structural damage. The reperfusion phase is accompanied by decreased tubular sodium reabsorption, which has been partly attributed to enhanced action of . In the present study we assessed whether intrarenal increases of accomplished by concomitant intrarenal hypoxanthine and intravenous xanthine oxidase (HX/XO) infusion would decrease or increase sodium excretion, and whether HX/XO infusion could be responsible for the diminished efficacy of renal blood flow (RBF) autoregulation in ischemia/reperfusion. Methods In the first group of Sprague-Dawley rats, renal sodium handling was measured before and during infusion. In the second group, renal hemodynamics and RBF autoregulation were assessed. Results Intrarenal infusion dramatically increased urine flow from 14.5 2.0 L/min to ...
Looking for effective renal plasma flow? Find out information about effective renal plasma flow. 1. the advancing of the tide 2. a stream of molten or solidified lava 3. an informal word for menstruation 4. Scot a. a marsh or swamp b. an inlet or basin... Explanation of effective renal plasma flow
Salt sensitivity of blood pressure (SSBP) and hypertension are common, but the underlying mechanisms remain unclear. Endoplasmic reticulum aminopeptidase 1 (ERAP1) degrades angiotensin II (ANGII). We hypothesized that decreasing ERAP1 increases BP via ANGII-mediated effects on aldosterone (ALDO) production and/or renovascular function. Compared with WT littermate mice, ERAP1-deficient (ERAP1+/-) mice had increased tissue ANGII, systolic and diastolic BP, and SSBP, indicating that ERAP1 deficiency leads to volume expansion. However, the mechanisms underlying the volume expansion differed according to sex. Male ERAP1+/- mice had increased ALDO levels and normal renovascular responses to volume expansion (decreased resistive and pulsatility indices and increased glomerular volume). In contrast, female ERAP1+/- mice had normal ALDO levels but lacked normal renovascular responses. In humans, ERAP1 rs30187, a loss-of-function gene variant that reduces ANGII degradation in vitro, is associated with ...
In the physiology of the kidney, renal blood flow (RBF) is the volume of blood delivered to the kidneys per unit time. In humans, the kidneys together receive roughly 25% of cardiac output, amounting to 1.1 L/min in a 70-kg adult male. RBF is closely related to renal plasma flow (RPF), which is the volume of blood plasma delivered to the kidneys per unit time. While the terms generally apply to arterial blood delivered to the kidneys, both RBF and RPF can be used to quantify the volume of venous blood exiting the kidneys per unit time. In this context, the terms are commonly given subscripts to refer to arterial or venous blood or plasma flow, as in RBFa, RBFv, RPFa, and RPFv. Physiologically, however, the differences in these values are negligible so that arterial flow and venous flow are often assumed equal. Renal plasma flow is the volume of plasma that reaches the kidneys per unit time. Renal plasma flow is given by the Fick principle: R P F = U x V P a − P v {\displaystyle RPF={\frac ...
Previously, we found increased expression of l-arginine metabolizing enzymes in both kidneys from two-kidney, one-clip (2K1C) hypertensive rats (Helle F, Hultstrom M, Skogstrand T, Palm F, Iversen BM. Am J Physiol Renal Physiol 296: F78-F86, 2009). In the present study, we investigate whether AT(1) receptor activation can induce the changes observed in 2K1C. Four groups of rats were infused with 80 ng/min ANG II or saline for 14 days and/or given 60 mg x kg(-1) x day(-1) losartan. Gene expression was studied in isolated preglomerular vessels by RT-PCR. Dose-responses to ANG II were studied in isolated preglomerular vessels with and without acute NOS inhibition [10(-4) mol/l N(G)-nitro-l-arginine methyl ester (l-NAME)]. Expressions of endothelial nitric oxide synthase (eNOS), caveolin-1, and arginase-2 were not changed by ANG II infusion. CAT1 (0.3 8 +/- 0.07 to 0.73 +/- 0.12, P , 0.05), CAT2 (1.14 +/- 0.29 to 2.74 +/- 0.48), DDAH2 (1.09 +/- 0.27 to 2.3 +/- 0.46), and arginase-1 (1.08 +/- 0.17 to ...
BioAssay record AID 232387 submitted by ChEMBL: Ratio of ED20 of MABP (mean arterial blood pressure) to the ED15 of RVR ( renal vascular resistance)..
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1. A method is described for perfusing the rabbits kidney in situ with hirudinized blood under conditions which permit adjustment and measurement of blood flow through the kidney.. 2. When blood flow through the perfused kidney amounts to 28-30 cc. per minute, fluid is eliminated from the ureter which is comparable in composition with that secreted before perfusion was begun.. 3. Rate of urine secretion by the perfused kidney is relatively constant when blood flow through the kidney is constant: it appears to be independent of changes of pressure in the renal circulation, provided (as in these experiments) changes in pressure do not cause changes in volume of blood flowing through it.. 4. Caffeine causes diuresis in the perfused kidney when the rate of blood flow through the kidney remains constant. The increase in blood flow which occurs in the intact animal as the result of the action of caffeine upon the renal vessels is therefore not an essential factor in caffeine diuresis.. 5. It is ...
Nitric oxide (NO) has an important role in maintaining basal renal blood flow (RBF) and glomerular filtration rate (GFR) in the developing kidney. However, renal endothelial NO synthase (eNOS) has not been localized in the developing kidney. The purpose of this study was to examine the expression and localization of eNOS in the developing rat kidney using immunohistochemistry and western blotting. Kidneys from 14 (E14)-, 16 (E16)-, 18 (E18)- and 20-day-old (E20) fetuses, 1 (P1)-, 4 (P4)-, 7 (P7)-, 14 (P14)- and 21-day-old (P21) pups, and adult rats were extracted for immunohistochemistry, and western blot analysis. In the adult rat kidney, eNOS was expressed strongly in the endothelial cells of the arcuate artery and the vascular bundle in the medulla. Endothelial cells of the glomerulus and peritubular capillary network were weakly labeled for eNOS. There was no eNOS immunoreactivity in the uriniferous tubules, including the proximal tubules. In the developing rat kidney, eNOS appeared in the ...
Although urinary sodium excretion is positively influenced by acute changes in renal perfusion pressure, micropuncture studies show highly conflicting results concerning the response of superficial proximal tubule sodium reabsorption to changes in renal perfusion pressure. In the present study, the changes of superficial proximal reabsorption to decreased and increased renal perfusion pressure were determined in rats by an in vivo microperfusion method. In vivo microperfusion was selected as the method to determine the proximal sodium reabsorption because this method made it possible to deliver a constant fluid and electrolyte load to the proximal tubule without the influence of possible changes of glomerular filtration rate. Renal perfusion pressure was decreased from normal pressure by inflating a suprarenal aortic cuff and was increased from the normal level by the occlusion of celiac and mesenteric arteries and the infrarenal aorta. Although fractional excretion of sodium (FENa) in the urine ...
The mechanism whereby renal nerves influence the renin-release response to aortic constriction was examined in a nonfiltering ureter-occluded kidney preparation in anesthetized dogs. The kidney was rendered nonfiltering by a combination of mannitol infusion and ureteral occlusion. Suprarenal aortic constriction reduced renal perfusion pressure to 61 +/- 7 mmHg and increased renin release from 16.7 +/- 4.1 to 26.1 +/- 6.0 U/min. At normal renal perfusion pressure, low-frequency renal nerve stimulation (0.25 Hz) increased renin release by 11.6 +/- 4.2 to 25.1 +/- 7.6 U/min. The effect of combined low-level renal nerve stimulation and aortic constriction on renin release was additive; renin release increased by 24.6 +/- 6.5 to 39.5 +/- 7.3 U/min. Propranolol or metoprolol, administered intrarenally at 2 microgram . min-1 . kg-1, abolished the renin-release response to low-level renal nerve stimulation at normal renal perfusion pressure. These data provide evidence that low-frequency renal nerve ...
The present study is the first to demonstrate that Ang II activates differing Ca2+ entry mechanisms in afferent and efferent arterioles. Our findings are thus consistent with evolving concepts concerning the segmental heterogeneity of activation mechanisms within the renal microvasculature. In the afferent arteriole, Ang II stimulates Ca2+ influx via dihydropyridine-sensitive and voltage-activated L-type Ca2+ channels, an activating mechanism that is absent in the efferent arteriole. In the efferent arteriole, Ang II stimulates Ca2+ influx through a signaling pathway that is nifedipine-insensitive and is not voltage-activated. Store depletion with CPA activates a nifedipine-insensitive Ca2+ entry in efferent myocytes that has a sensitivity to SKF 96365 identical to that of the Ca2+ influx activated by Ang II in the intact arteriole. This store-operated Ca2+ entry mechanism is absent in the afferent arteriole.. Our findings agree with those of previous studies assessing renal microvascular ...
Pathological renal mobility can cause a functional disorder, which is an indication for nephropexy. The aim of this study was to examine functional renal capacity before and after nephropexy applying radionuclide tests and to compare the...
A dye-dilution method of measuring renal hemodynamics in man has been described. The method requires catheterization of both the renal artery and the renal vein, a single injection of dye into the renal artery, and recording of the venous dilution curve by means of a cuvette densitometer.. The method was evaluated in 11 normal subjects, eight patients with acute anuric renal failure, and 13 patients with chronic renal disease. In 26 instances the PAH clearance and the PAH-extraction ratio were determined simultaneously. The dye-PAH flow ratio averaged 0.98 for the whole series. The limitations of the dye method have been discussed.. The dye method probably makes it possible to estimate the blood flow distribution within the human kidney. The available data indicate that cortical blood flow in the normal kidney ranges from 80 to 93% of the total flow, with a mean transit time of 5 to 10 sec. The calculated cortical vascular volume ranges from 52 to 78% of the total volume. The extracortical flow ...
Glomerular filtration rate and renal plasma flow in patients with essential hypertension before and after tratment with alprenolol. ...
The movement of blood through the vessels. It is pulsatile in the large arteries, diminishing in amplitude as it approaches the [capillaries. In the veins it is nonpulsatile. The flow in arteries is the result of ventricular ejection; in the veins it is a result of a number of factors including respiratory movement, muscle compression and the small residuum of arterial pressure. Effective renal blood flow (ERBF) That portion of the total blood flow through the kidneys that perfuses functional renal tissue such as the glomeruli. Laminar blood flow Blood flowing through a large blood vessel moves forward in a series of concentric laminae that slide over each other like a telescoping radio aerial. The central lamina moves fastest; the outer layer may be stationary. Renal blood flow, effective The amount of blood flowing to the parts of the kidney that are involved with the production of constituents of urine. It is that portion of the total renal blood flow that perfuses functional renal tissue ...
Quantitative angiography and intravascular Doppler techniques have been extensively used for evaluation of coronary anatomy (12) and for the assessment of coronary blood flow reserve (13). These techniques have also been validated and used for the measurements of changes in RAD and RBF (9-11,14-16). Our group has used these methods to gain further insight into the renal circulatory effect of various therapeutic interventions in patients with HF (10,17,18). The use of these techniques in the present study has indicated that compared with its systemic effect the renal circulatory action of nesiritide is more complex. A bolus administration followed by continuous infusion of the standard recommended dose of the drug was associated with a progressive dilation of the large conductance renal arteries, but at the same time a fall in VTI and, therefore, no significant change in RBF and only a small and statistically insignificant fall in RVR. The findings of this unique response to nesiritide are ...
This trial compared the pharmacodynamics and pharmacokinetics of tolvaptan in patients with autosomal dominant polycystic kidney disease. The primary endpoint
Background: Increased activity of the renal-vascular renin-angiotensin system (RAS) is a leading mechanism for chronic kidney disease (CKD) in obesity. Low vitamin D levels are associated with increased RAS activity, obesity, and the development of CKD; we hypothesized that vitamin D3 therapy in obesity would lower renal-vascular RAS activity and thus increase the renal-vascular sensitivity to angiotensin II (AngII) akin to an ACE inhibitor.. Methods: 14 morbidly obese subjects (BMI 36 kg/m2) with hypertension, pre-diabetes, 25(OH)D,25 ng/mL, and normal renal function were studied. Anti-hypertensive medications were withdrawn for up to 3 months, and subjects completed a controlled sodium diet for 1 week prior to study visits, which occurred before and after 15,000 IU/daily of vitamin D3 for 1 month. At each study visit, renal plasma flow (RPF, via p-aminohippurate clearance) was measured during an infusion of AngII (1 ng/kg/min) in triplicate at baseline, 45, and 90 mins. Subjects were then ...
The surge of technological advancements has changed the way we treat diseases. In the realm of nephron sparing surgery there is a raging debate on the role of ischemia in the preservation of renal function. We set about discussing this issue by conducting a literature search of pertinent articles of interest. Our narrative synthesis of these articles sheds light on the matter as well as discusses recent innovation that modifies or even eliminates the use of mechanical ischemia in renal surgery.. ...
Objective: We compared the renal and systemic vascular (renovascular) response to reducing bioavailable nitric oxide in patients with type 2 diabetes without nephropathy of African and Caucasian heritage.. Method: Under euglycaemic conditions, renal blood flow was measured by a constant infusion of paraminohippurate and changes in blood pressure and renal vascular resistance estimated before and after an infusion of L-Ng-monomethyl-l-arginine (L-NMMA).. Results: In the African heritage group there was a significant fall in renal blood flow (Δ − 46.0 mls/min/1.73 m2;p,0.05) and rise in systolic blood pressure (Δ10.0 [2.3 - 17.9] mmHg; p=0.017) which correlated with an increase in renal vascular resistance (r2=0.77; p=0.004).. Conclusions: The renal vasconstrictive response associated with nitric oxide synthase inhibition in this study may be of relevance to the observed vulnerability to renal injury in patients of African heritage.. ...
Role of the Afferent and Efferent Arterioles The kidneys have an autoregulatory system to keep their blood flow and perfusion constant over a wide range of blood pressures. Unlike perfusion of all other organs, perfusion of the kidney is not regulated to maintain organ nutrition but to retain its filtration functions. The glomerular hydrostatic pressure is regulated mainly by the balance of vascular tone in the afferent and efferent arterioles. Owing to this exceptional arrangement of resistance vessels in series, before and after the glomerulus, renal blood flow (RBF) and glomerular filtration rate (GFR) can be regulated independently.
It causes dry kali and constipation, and it can lasix and renal function congestion and decrease sexual function. But for many women who have suffered from headaches and compulsions for years, it is increasing to be on it out its lasix and renal functions. With chromosome from the CIBA-Geigy Pharmaceutical company. Two seed have written to 14 different companies about the available staggering price increases for high drugs used to treat everything He yielded simvastatin, the preferred equivalent of cholesterol drug Zocor, and clomipramine hydrochloride, the uterine version of antidepressant Anafranil. REM p. Stephen, R. Diuretics are useful in the management of most patients with CKD. .. Therefore, in patients with kidney failure, the plasma half-life of furosemide is prolonged. Second, as expected from the pharmacology of furosemide, the diuretic effect of furosemide depends on renal blood flow, and the function of.. ...
The arcuate artery of kidney is a vessel of the renal circulation system. It can be found at the edge of the renal medulla and renal cortex. The artery got its named because of how the renal medulla is shaped (like an arc).
Having established that the calcium antagonists, including vascular selective calcium antagonists such as amlodipine, have a favourable effect on renal haemodynamics and function (Chapter 10), and...
Chemical: Noradrenaline constricts interlobular and afferent arterioles. Angiotensin 11 constricts efferent arterioles , afferent arterioles. Dopamine (made in kidney) vasodilates. Acetylcholine vasodilates. Prostaglandins inc. bl flow in cortex, dec. bl flow in medulla.. - Neural: SNS -, dec bl flow. Fall of BP, vasoconstrictor response includes renal bl flow.. - Autoregulation: contractile response of smooth muscle of afferent arteriole to stretch (BP). NO may be involved. Angiotensin 11 plays a role in constricting efferent arterioles, maintaining GFR,. ...
The efferent arteriole carries blood away from the glomerulus. Because it has a smaller diameter than the afferent arteriole, it creates some resistance to blood flow, producing the back-up of blood in the glomerulus which creates higher pressure in the glomerular cavity.. ...
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TY - CONF. T1 - MR nephrography of 10 healthy volunteers - technique and normal standards or renal perfusion. AU - Preidler, K.. AU - Szolar, D.. AU - Horina, J. H.. AU - Ranner, G.. AU - Stollberger, Rudolf. AU - Schreyer, H.. AU - Ebner, F.. PY - 1994. Y1 - 1994. M3 - Poster. ER - ...
RESULTS Compared with baseline values, GFR (171 ± 20 to 120 ± 15 mL/min/1.73 m2) and filtration fraction (FF, 0.24 ± 0.06 to 0.18 ± 0.03) declined in hyperfilterers (ANOVA P ≤ 0.033), and renal vascular resistance increased (0.0678 ± 0.0135 to 0.0783 ± 0.0121 mmHg/L/min, P = 0.017). GFR and FF did not change in normofiltering subjects. In contrast, the radial augmentation index decreased in hyperfiltering (1.2 ± 11.7 to −11.0 ± 7.8%) and normofiltering (14.3 ± 14.0 to 2.5 ± 14.6%) subjects (within-group changes, ANOVA P ≤ 0.030). The decline in circulating aldosterone levels was similar in both groups. ...
MAJID, DEWAN S. A., EDWARD W. INSCHO, and L. GABRIEL NAVAR. "P2 Purinoceptor Saturation by Adenosine Triphosphate Impairs Renal Autoregulation in Dogs." Journal of the American Society of Nephrology 10.3 (1999): 492-498. Web. 08 April. 2020. ...
Why? In prerenal failure like hemorrhagic shock, you have less renal blood flow, you will filter less and GFR will decrease. When GFR decreases, it gives the proximal tubule more time to reabsorb urea. Thus, there is an increase in serum urea ...