Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A heptapeptide solution in acetate buffer (pH = 4, 150 micrograms/kg) of the amino acid sequence common to ACTH, alpha- and beta-MSH and lipotrophin, when injected intravenously into rabbits produced an increase in total lipids, cholesterol and free fatty acids after 1 h and a decrease in plasma calcium and phosphate after 2 h. No significant modification in the amount of creatinine, uric acid, urea, total proteins, CO2, Cl-, K+ or Na+ was observed.
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PMID:In-vivo hypocalcaemic, hypophosphataemic and hyperlipaemic activities in the common peptide sequence of adrenocorticotrophin, melanocyte-stimulating hormone and lipotrophin. 630 30

Chronic liver disease may be accompanied by disturbed sodium and water homeostasis. There is usually sodium retention and ascites. However, spontaneous natriuresis has also been reported in humans and experimental animals with liver cirrhosis. Chronic hypercortisolism, which may occur in dogs with advanced liver disease, is known to induce the inhibition of the osmostimulation of vasopressin (AVP) release. We have therefore investigated the osmoregulation of AVP release in 11 dogs with chronic hypercortisolism associated with advanced liver dysfunction and hepatic encepahlopathy and in 10 control dogs. Basal pituitary-adrenocortical activity was investigated by measuring the concentration in multiple plasma samples of adrenocorticotropin (ACTH), alpha-melanocyte-stimulating hormone (MSH), and cortisol and the cortisol:creatinine ratio in 24-hr urine. Urine specific gravity was also measured. The feedback regulation of the system was investigated by measuring these hormones in plasma after an intravenous (iv) injection of 0.01 mg/kg of dexamethasone. The osmoregulation of the release of AVP was investigated by the intravenous infusion of a 20% NaCl solution at a flow rate of 0.03 ml/kg for 2 hr and the measurement of AVP in plasma sampled at 20-min intervals. The AVP release was analyzed in terms of the threshold osmolality at which it commenced and the sensitivity, which reflects the magnitude of the response. All dogs had highly increased urinary cortisol:creatinine ratios, ranging from 21 to 210 x 10(-6) (normally < 10 x 10(-6)). The mean basal plasma concentrations of the three pituitary-adrenocortical hormones were significantly increased. ACTH values were 35 to 146 ng/l (normally, 14 to 68), MSH values were 26 to 118 ng/l (normally, 10 to 36), and cortisol values were 88 to 194 nmol/l (normally, 23 to 112). The feedback inhibition of the secretion of ACTH and cortisol in response to dexamethasone was unaffected. Urine specific gravity was significantly decreased. The regulation of AVP release was found to be abnormal in all dogs with hepatic encephalopathy. The osmotic threshold at which the release of AVP was induced was abnormally high in seven of the dogs with liver disease and in the normal range in one. It could not be determined in three dogs. The sensitivity of AVP release in response to increasing plasma hypertonicity was normal in two dogs and decreased in nine. In three dogs, there was no increase in AVP release. None of the dogs had normal values for both the sensitivity and the threshold.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Chronic glucocorticoid excess and impaired osmoregulation of vasopressin release in dogs with hepatic encephalopathy. 762 76

The objective of the study was to determine the sensitivity with which an adenoma of the pars intermedia of the pituitary gland can be predicted in horses by measuring the basal concentrations of glucose, cortisol, adrenocorticotropin (ACTH), and insulin, the urinary concentration of corticoids, the urinary corticoid:creatinine ratio, and the plasma cortisol concentration after the administration of 25 IU of ACTH intravenously. The records of 24 cases of histologically confirmed equine pituitary pars intermedia adenomas were used. An adenoma of the pars intermedia of the pituitary gland in horses was predicted with a sensitivity of 100, 100, and 92% for basal plasma ACTH (n = 16), the urinary corticoid:creatinine ratio (n = 7), and basal plasma insulin (n = 12), respectively. The sensitivity of the ACTH-stimulation test was 79% (n = 14).
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PMID:Laboratory diagnosis of equine pituitary pars intermedia adenoma. 762 78

Endogenous opioid peptides play an important role in the pathogenesis of uraemic syndrome. The effect of insulin-induced hypoglycaemia on serum beta-endorphin (BE) concentration was studied in 27 uraemic patients and in 14 healthy subjects. Despite elevated basal BE level, that correlated positively with serum creatinine, uraemic patients showed a normal BE secretory pattern. No differences were found between uraemic patients on conservative and those on haemodialysis treatment. The influence of haemodialysis treatment on BE secretion requires further investigations.
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PMID:Serum beta-endorphin in non-dialysed and haemodialysed patients with chronic renal failure. 802 16

To examine the changes of plasma beta-endorphin (beta-EP) concentrations in response to various heavy-resistance exercise protocols, eight healthy male subjects randomly performed each of six heavy-resistance exercise protocols, which consisted of identically ordered exercises carefully designed to control for the repetition maximum (RM) resistance (5 vs. 10 RM), rest period length (1 vs. 3 min), and total work (joules). Plasma beta-EP, ammonia, whole blood lactate and serum cortisol, creatine kinase, urea, and creatinine were determined preexercise, midexercise, immediately postexercise, and at various time points after the exercise session (5 min-48 h), depending on the specific blood variable examined. Only the high total work-exercise protocol [1 min rest, 10 RM load (H10/1)] demonstrated significant increases in plasma beta-EP and serum cortisol at midexercise and 0, 5, and 15 min postexercise. Increases in lactate were observed after all protocols, but the largest increases were observed after the H10/1 protocol. Within the H10/1 protocol, lactate concentrations were correlated (r = 0.82, P < 0.05) with plasma beta-EP concentrations. Cortisol increases were significantly correlated (r = 0.84) with 24-h peak creatine kinase values. The primary finding of this investigation was that beta-EP responds differently to various heavy-resistance exercise protocols. In heavy-resistance exercise, it appears that the duration of the force production and the length of the rest periods between sets are key exercise variables that influence increases in plasma beta-EP and serum cortisol concentrations. Furthermore the H10/1 protocol's significant challenge to the acid-base status of the blood, due to marked increases in whole blood lactate, may be associated with mechanisms modulating peripheral blood concentrations of beta-EP and cortisol.
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PMID:Effects of different heavy-resistance exercise protocols on plasma beta-endorphin concentrations. 844 27

gamma-Aminobutyric acid (GABA) is the principal depressant neurotransmitter system, but its possible role in the regulation of the hypothalamic-pituitary-adrenocortical (HPA) axis has not yet been investigated in the dog. Moreover, GABA is one of the factors underlying the syndrome of hepatic encephalopathy (HE), and in dogs with HE, the regulation of the HPA axis is deranged. We have therefore investigated the role of the GABA system in the regulation of the HPC system in 10 healthy dogs and 10 dogs with HE due to congenital portosystemic shunts. The effect of an intravenous injection of the GABA antagonist bicuculline on the release of adrenocorticotropin (ACTH), alpha-melanotropin (MSH), and cortisol was measured in plasma. In healthy dogs, a dose of 1.0 mg/kg caused a marked release of ACTH, MSH, and cortisol, but doses of 0.001 to 0.5 mg/kg produced an inconsistent or no response. The high release of MSH after bicuculline administration indicated that the effect of GABA was predominantly in the neurointermediate lobe of the pituitary. In order to investigate whether the effect of GABA was exerted in the pituitary or at a suprapituitary level, the effect of incubation with GABA on basal and corticotropin-releasing hormone-induced ACTH release was measured in primary cultures of anterior and neurointermediate lobe cells from healthy dogs, and no response was observed. We conclude that in healthy dogs, GABA inhibits the release of ACTH and MSH from the neurointermediate lobe of the pituitary at a suprapituitary level. In dogs with HE, 1.0 mg/kg of bicuculline caused virtually no stimulation of the secretion of ACTH, MSH, or cortisol, indicating deranged GABAergic neurotransmission in HE. This may be explained by an increased GABA tone that prevents the effect of the antagonist. Such a high GABA tone associated with HE has been documented in several other species. Dogs with HE had significantly increased basal levels of ACTH, MSH, and cortisol in plasma, and their cortisol:creatinine ratios in 24-hr urine samples (63 +/- 14.10(-6)) were higher than those of healthy dogs (9 +/- 2.10(-6)). An increased basal HPA activity in dogs with HE is not in agreement with augmented GABAergic inhibition, but this contradiction may be explained by the predominance of effects of dopaminergic disinhibition that has been reported in such dogs.
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PMID:GABAergic inhibition of the pituitary release of adrenocorticotropin and alpha-melanotropin is impaired in dogs with hepatic encephalopathy. 862 16

Pituitary function was assessed before and after transsphenoidal hypophysectomy in 39 dogs with pituitary-dependent hyperadrenocorticism (PDH). Anterior pituitary function was investigated using combined administration of four hypophysiotropic releasing hormones (corticotropin-releasing hormone (CRH), GHRH, GnRH, and TRH) with measurements of ACTH, cortisol, GH, LH, prolactin (PRL), and TSH Pars intermedia function was assessed by measurements of basal plasma alpha-MSH concentrations and adrenocortical function by baseline urinary corticoid/creatinine ratios. At eight weeks after hypophysectomy basal plasma ACTH, cortisol, GH, LH, PRL, and TSH concentrations were significantly lower than before surgery. In seven dogs with elevated alpha-MSH concentrations, the values returned to the normal level after surgery. In the combined anterior pituitary function test there were no plasma GH, LH, PRL, and TSH responses to stimulation, whereas plasma ACTH and cortisol responses were small but significant. Remission of hyperadrenocorticism was obtained in 35 dogs and recurrences occurred in 3 of these within 16 months postoperatively. At 8 weeks after hypophysectomy, these 3 dogs were not discernible, with respect to residual pituitary and adrenocortical function, from the 32 dogs with persisting remission. Urinary corticoid/creatinine ratios in the latter group of dogs did not increase during 22 months after hypophysectomy. In contrast to the presurgical findings, at 8 weeks after hypophysectomy there were significant positive correlations between baseline urinary corticoid/creatinine ratios and basal levels and responses for ACTH, indicating return to normal function of the pituitary-adrenocortical axis. It is concluded that among the adenohypophyseal cells present in the sella turcica after hypophysectomy, the corticotropes have a distinct behavior. Much more so than the other cell types, the unaffected corticotropes tend to remain functional, or a repressed reserve fraction of corticotropes may become functional. This may be due to the removal of the hypothalamic influence of a postulated corticotropin-release inhibiting factor or a diminished inhibitory influence of a postulated paracrine factor. The corticotropes may maintain normocorticism, but may also lead to mild recurrence after relatively long periods of remission.
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PMID:Residual pituitary function after transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism. 948 98

Ten dogs with pituitary-dependent hyperadrenocorticism (PDH) received 2 mg/kg of L-Deprenyl once daily for 6 months. Monthly patient assessment consisted of evaluation of the owner's daily observation protocol, a standardized owner questionnaire, physical examination, CBC, biochemical profile, determination of the urine cortisol/creatinine ratio (UC/C), low-dose dexamethasone suppression (LDDS) test, corticotropin releasing hormone (CRH) test, and adrenal ultrasonography. At the beginning and the end of the study, an adrenocorticotropic hormone (ACTH) stimulation test and computed tomography also were performed. Two dogs developed neurologic signs and 2 dogs developed acute pancreatitis. An increase in activity, decrease in polyphagia, and decrease in panting were reported by 6, 4, and 2 owners, respectively. Seven owners believed that water intake decreased, but this was confirmed in only 3 dogs. Water intake increased in 2 dogs and remained unchanged in 5 dogs. The condition of the hair coat and skin improved in 2 dogs, worsened in 3, and remained unchanged in 5. Urine specific gravity, urine osmolality, ACTH test results, UC/C, and adrenal gland size did not change significantly throughout the study. In 4 of 8 dogs, LDDS was abnormal at the start of the study but normal at the end of the study, and in 2 dogs, the opposite occurred. Marked individual variation was noted in the CRH test, with a tendency for smaller increases in ACTH toward the end of the study. A marked increase in hypophyseal tumor size occured in 4 dogs. Treatment with L-Deprenyl resulted in improvement, deterioration, and stagnation of clinical signs in 2, 4, and 4 dogs, respectively. The results of this study indicate that L-Deprenyl cannot be recommended as the sole treatment for canine PDH.
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PMID:The efficacy of L-Deprenyl in dogs with pituitary-dependent hyperadrenocorticism. 1044 18

A decreased ratio of branched-chain amino acids (BCAA) to aromatic amino acids (AAA) is considered an important pathogenetic factor in hepatic encephalopathy (HE). A relationship between the deranged BCAA/AAA ratio and dopaminergic dysfunction through the formation of "false" neurotransmitters has been postulated. The intermediate lobe of the pituitary is more pronounced in dogs than in humans and because it is primarily under dopaminergic inhibitory influence, it may serve as an indicator of alterations in dopaminergic neurotransmission. We investigated the effects of a diet with a high BCAA/AAA ratio (HR) and an isonitrogenous diet with a low BCAA/AAA ratio (LR) on several physical and biochemical parameters including pituitary function in dogs with portocaval shunts and 40% hepatectomy and in sham-operated pair-fed controls, in a double-blind, randomized cross-over study. Portocaval-shunted dogs had hyperammonemia (33+/-3 microM (mean +/- SEM) before and 214+/-21 after surgery)) and signs of HE. Their BCAA/AAA ratio in plasma and CSF decreased from 4.3+/-0.3 and 2.3+/-0.3 before surgery to 1.3+/-0.1 and 0.5+/-0.1 after surgery, respectively. These parameters remained unaltered in the control dogs. The consumption of the LR diet was significantly higher than consumption of the HR diet. In the portocaval-shunted dogs, plasma ammonia concentration was higher on the HR diet than on the LR diet (344+/-52 v 246+/-45) and the HE grade was worse. The BCAA/AAA ratio remained abnormal in HE dogs during the feeding of both diets. The basal and haloperidol-stimulated release of alpha-melanotropin and cortisol in plasma were not significantly different between or within groups during any period. In contrast, urinary cortisol excretion was increased in the HE dogs after surgery (urinary cortisol:creatinine ratio (x10(-6)) 8.5+/-1.4 before and 30.4+/-8.9 after surgery). The basal plasma concentration of adrenocorticotropin in HE dogs was decreased after surgery (68.3+/-10.2 ng/L before and 40.8+/-4.4 after surgery). This indicates a non-pituitary-dependent hyperresponsiveness of the adrenals. We conclude from these results that chronic HE in dogs is not associated with an abnormal dopaminergic neurotransmission at least at the level of the pituitary, and that it is not the content of the dietary neutral amino acids but rather the total protein intake that may have a beneficial effect on HE.
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PMID:Effects of a branched-chain amino acid-enriched diet on chronic hepatic encephalopathy in dogs. 1048 12

1. The role of the kidneys in the maintenance of normal foetal plasma (FP) composition and hormone concentrations was examined in the present study. Five ovine foetuses were chronically cannulated and nephrectomized (nephx) at 100 +/- 1 days of gestation and maintained for 14 days. These were compared to five intact control foetuses. 2. Four hours after nephx, FP renin concentrations were significantly lower than in control foetuses. By 48 h, renin concentrations in nephx foetuses were below the level of detectability of the assay. Foetal plasma aldosterone concentrations declined in nephx foetuses, but were not significantly different to those in control foetuses (P = 0.08). 3. During the second week, the nephx foetuses were significantly hypoxic, but FP erythropoietin concentrations were not increased. Adrenocorticotropic hormone (ACTH) and cortisol concentrations, when measured on day 14, were not different between the two groups. Adrenocorticotropic hormone levels were correlated with adrenal weight at post-mortem. 4. Foetal plasma creatinine, magnesium and phosphate concentrations in nephx foetuses increased, eventually reaching values approximately twice that in controls. Foetal plasma chloride levels decreased continuously in nephx foetuses, eventually being 23 mmol/L lower than controls. Maternal plasma composition was unchanged. 5. Total foetal fluid (amniotic + allantoic) volumes were reduced when measured at post-mortem on day 14 after nephx. The composition of both fluids was significantly altered in the nephx foetuses compared with controls. 6. Fetuses can survive in utero for 2 weeks after bilateral nephrectomy. However, there are multiple changes in plasma composition that may compromise foetal survival in the long term.
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PMID:Foetal fluid balance and hormone status following nephrectomy in the foetal sheep. 1056 5


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