Glucocorticoid-dependency on GH secretion and tumor growth in a GH-producing pituitary adenoma with Cushing's syndrome.
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We report a rare case of a 40-year-old woman with Cushing's syndrome and Acromegaly. At the age of 28 she was diagnosed with Cushing's syndrome due to a left adrenal tumor concomitant with a GH-producing pituitary tumor. Before adrenal surgery her basal GH levels were extremely high and CT scanning revealed a high-density mass in the sella turcica. A 28 g left adrenocortical adenoma was removed by adrenalectomy. During the four months after the adrenalectomy, basal GH levels dramatically decreased and the high-density mass detected by CT scanning had disappeared but the basal GH levels and IGF-1 had not been normalized. She gradually became acromegalic in the twelve years after the adrenalectomy. At the age of 40 CT scanning showed reappearance of the pituitary tumor. In order to examine the glucocorticoid dependency on GH secretion, we compared the GH secretion in a series of endocrinological tests before and after oral 8 mg dexamethasone administration for 7 days. There was no difference between before and after dexamethasone administration in the GH secreting pattern, but basal GH levels were apparently increased after dexamethasone treatment. Transsphenoidal surgery was done and pathological examination showed a GH-producing pituitary adenoma. In vitro, dexamethasone increased GH secretion from the cultured GH-producing adenoma cells in a dose-dependent manner. In this case, both GH secretion and pituitary tumor growth seemed to be dependent on glucocorticoid. (+info)
Effect of adrenalectomy and corticosterone on cocaine-induced sensitization in rats.
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Effects of adrenalectomy (ADX) and corticosterone (CORT) on the development and expression of sensitization to the locomotor effect of cocaine (COC) were studied in rats. Sensitization was evoked by 5 daily injections of COC (10 mg/kg) and measured after a challenge dose of the drug (10 mg/kg) after a 5-day withdrawal (on day 10 of the experiment). ADX, performed before the start of COC administration, completely blocked the manifestation of COC-induced sensitization. In contrast, ADX performed on animals already sensitized to COC did not affect the sensitized locomotor activity response to a challenge dose of COC (on day 18). Pretreatment with CORT, 10 mg/kg, but not 5 mg/kg, before each of the 5 daily COC injections facilitated the development of COC sensitization, tested after a 5-day withdrawal. When pretreated with CORT alone (10 mg/kg), the challenge dose of COC administered on day 10 induced cross-sensitization to CORT. CORT (10 mg/kg) injected acutely before COC on day 10, potentiated the expression of COC sensitization. When given alone, on day 10 CORT (5-10 mg/kg) induced an increase in the locomotor activity of rats pretreated daily (5 injections) with COC. No drug treatment induced conditioned locomotion, as measured after saline challenge on day 8. Our results indicate that CORT facilitates the development and expression of COC sensitization, while ADX blocks the initiation of the behavioral phenomenon only. Moreover, there takes place cross-sensitization between CORT and COC, which indicates a close relationship between the drug-related mechanism and behavioral sensitization. (+info)
The proportion of cells with a high density of ED2 (ED2high cells) in peritoneal cells from old rats was significantly lower than that from young rats. The expression of major histocompatibility complex class II (MHC class II) molecules, the antigen presentation, production of interleukin (IL)-1beta and IL-6, and nuclear factor-kappaB activity in ED2high cells were markedly higher than those in cells with a low density of ED2 (ED2low cells), although no significant difference was observed in the expression of MHC class II molecules and the antigen presentation between ED2high cells from young and old rats. Meanwhile, basal corticosterone concentration in serum and glucocorticoid (GC) receptor mRNA expression in peritoneal cells increased significantly in old rats. The proportion of ED2high cells was increased by adrenalectomy in young rats. Furthermore, nuclear translocation of GC receptor was observed in ED2low cells, whereas GC receptor was detected in cytoplasmic extracts from ED2high cells. These results suggest that the decrease in functional ED2high macrophages with age results in the age-associated decline of immune responses, which is regulated, in part, by the basal GC concentration. (+info)
Laparoscopic operative technique for adrenal tumors.
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BACKGROUND AND OBJECTIVES: Laparoscopy has acquired an unquestionable position in surgical practice as a diagnostic and operative tool. Recently, the laparoscopic approach has become a valuable option for adrenalectomy. This paper reports, in detail, our experience of laparoscopic adrenalectomy performed for adrenal tumors. METHODS: We performed 12 laparoscopic adrenalectomies from October 29, 1997 to October 31, 1998. The technique of laparoscopic adrenalectomy is described thoroughly in all relevant details for either left or right-sided adrenal lesions. RESULTS: The presented technique of laparoscopic adrenalectomy in all 12 cases provided good and relatively simple exposure of the immediate operative area. All relevant vascular elements were safely controlled, adrenal tumors could be successfully removed, and adequate hemostasis was achieved. No intraoperative or postoperative complications were observed. CONCLUSIONS: Laparoscopic adrenalectomy is a safe alternative to open surgery and is preferred for most patients because of shorter postoperative hospital stay and less postoperative discomfort. (+info)
Relationship of interstitial fluid volume to alveolar fluid clearance in mice: ventilated vs. in situ studies.
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Our recent report (Garat C, Carter EP, and Matthay MA. J Appl Physiol 84: 1763-1767, 1998) described a new method to measure alveolar fluid clearance (AFC) in an in situ mouse preparation. However, in vivo preparations may be more suitable for studying alveolar fluid transport under some pathological conditions. Therefore, we developed a ventilated mouse model and compared AFC in the ventilated and the in situ mouse models. After 15 min, AFC was similar in both groups, but, after 30 min, AFC was 38% slower in the in situ mice (P < 0.05). Bilateral adrenalectomy and propranolol did not inhibit AFC after 15 min. Amiloride inhibited 90% of AFC in both groups. To evaluate the mechanism for the slower AFC in the in situ mouse preparation, we measured the extravascular lung water and calculated interstitial fluid volume. Extravascular lung water and interstitial fluid volume were greater in the in situ mice than in the ventilated mice at 30 min (P < 0.05). These results indicate that mouse AFC is fast, highly amiloride sensitive, and independent of endogenous catecholamines during the first 15 min. Accumulation of interstitial fluid probably plays an important role in slowing AFC in the in situ mouse lung model at later time intervals. These mouse models will be useful to quantify alveolar epithelial fluid transport under pathological conditions. (+info)
Primary aldosteronism in pregnancy.
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Aldosteronism is a rare complication of pregnancy. We report a case of a 26-year-old woman who became pregnant soon after a diagnosis of primary aldosteronism due to left adrenal adenoma was made. Only oral potassium supplementation was required in addition to routine prenatal care until 36 weeks' gestation. Subsequently, antihypertensive medication was needed to control elevated blood pressure. A healthy male infant was delivered by cesarean section because of abruptio placentae. The postoperative course was uneventful. Left adrenalectomy was conducted eight months after delivery under laparoscopic visualization. In this case report, we discuss management of aldosteronism in pregnancy and review the literature. (+info)
Regulation by glucocorticoids of expression and activity of rBSC1, the Na+-K+(NH4+)-2Cl- cotransporter of medullary thick ascending limb.
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To assess whether glucocorticoids regulate rBSC1, the apical Na(+)-K(+)(NH(4)(+))-2Cl(-) cotransporter of kidney medullary thick ascending limb (MTAL), studies were performed in normal rats, adrenalectomized (ADX) rats, and ADX rats infused with dexamethasone for 6 days. The effects of dexamethasone on rBSC1 were also studied in vitro using isolated rat MTAL segments. Cotransport activity was estimated by intracellular pH measurements; rBSC1 protein was quantified in MTAL crude membranes by immunoblotting analysis, and mRNA was quantified by quantitative reverse transcription-polymerase chain reaction. The abundance of rBSC1 protein and mRNA increased in ADX rats infused with dexamethasone compared with ADX rats (p < 0. 04). In addition, application of dexamethasone for 1-3 h to MTALs caused rBSC1 protein and mRNA abundance and cotransport activity to significantly increase in a hyperosmotic medium (450 mosmol/kg of H(2)O) containing 0.7 nm arginine vasopressin, which is an in vitro experimental condition that resembles the in vivo MTAL environment. Results obtained in various media and with 8-bromo-cAMP indicated that stimulation of rBSC1 expression by glucocorticoids required interactions between glucocorticoid receptor- and cAMP-dependent factors. Up to 100 nm d-aldosterone had no effect on cotransport activity in vitro. Thus glucocorticoids directly stimulate MTAL rBSC1 expression and activity, which contributes to glucocorticoid-dependent effects on the renal regulation of acid-base balance and urinary concentrating ability. (+info)
The importance of the hypothalamo-hypophyseal-adrenal axis to the anti-inflammatory actions of the kappa-opioid agonist PNU-50,488H in rats with adjuvant arthritis.
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Possible contributions of the hypothalamo-hypophyseal-adrenal axis to the development of adjuvant-induced arthritis and therapeutic actions of the prototypical kappa-opioid agonist PNU-50,488H (PNU-50) were studied in DA rats. Paw edema, nociception, histological and radiological joint damage, and tumor necrosis factor-alpha release by peritoneal macrophages were measured in adrenalectomized (ADX) and sham-operated (SHO) arthritic animals (drug-treated and untreated groups). Disease developed earlier in ADX rats (paw edema was first apparent 11 days postadjuvant compared with day 13 in SHO animals) and remained more severe in that group. Twice-daily PNU-50 treatment completely prevented the development of edema in the SHO group but was effective in the ADX animals only on day 18. PNU-50 substantially reduced the pooled severity index (combined quantitative edema, histological and radiological assessments) at day 18 in both SHO and ADX rats and to an equal extent. During disease development, the paws of SHO, but not ADX, rats became hyperalgesic; paradoxically, ADX animals were hyperalgesic during PNU-50 treatment, but the drug produced analgesia in SHO animals. Compared with cells harvested from healthy animals, macrophages from arthritic rats released about twice as much tumor necrosis factor-alpha after lipopolysaccharide stimulation. It was concluded that the hypothalamo-hypophyseal-adrenal axis influences the development of adjuvant arthritis and plays a partial role in the therapeutic action of the kappa-agonist PNU-50. (+info)