Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The medullary thick ascending limb (MAL), but not the medullary collecting tubule (MCT), has been shown to have an impaired adenylate cyclase (AC) responsiveness to ADH and a selective hypoplasia in Brattleboro diabetes insipidus (DI) rats. Since chronic ADH administration has been found to increase epithelium volume and basolateral membrane surface area in MAL but not in MCT, we investigated whether chronic ADH infusion would affect the hormone-sensitive AC and the Na-K-ATPase activity--two markers of the basolateral membrane--in single micro-dissected portions of thick ascending limb and collecting tubule in DI rats. Results indicate that 1. in MAL of ADH-treated rats, AC responses to in vitro AVP and glucagon and Na-K-ATPase activity increased to the same extent as did epithelium volume (60-80%); 2. changes in the other segments were independent of any morphological alteration. In the cortical thick ascending limb, AVP and glucagon-sensitive AC decreased by 30-40% whereas Na-K-ATPase activity did not change. In the collecting tubule, AC response to in vitro AVP was not altered by ADH-treatment but glucagon-sensitive AC dropped by 50% and Na-K-ATPase activity doubled, independently of any variation in plasma aldosterone and glucagon levels. These results show that, in the MAL, the ADH-induced variations in enzyme activity are a reflection of the enlargement of the basolateral membrane surface area. Further studies are needed to clarify the origin of enzymatic alterations in the other segments.
 ...
PMID:Influence of chronic ADH treatment on adenylate cyclase and ATPase activity in distal nephron segments of diabetes insipidus Brattleboro rats. 299 94

Physical injury of any sort--accidental injury, burns or elective surgery--provokes an immediate neuroendocrine response. Neural input arising from the cerebral cortex, damaged tissues and receptors detecting fluid loss leads to increased secretion of ACTH, growth hormone, prolactin and vasopressin from the pituitary, and to a general activation of the sympathetic nervous system, with rises in adrenaline and noradrenaline concentrations. Secondary changes include stimulation of cortisol and aldosterone and inhibition of insulin and somatomedin secretion. The glucagon concentration and plasma renin activity may also be increased, either immediately or after a delay. The duration of these responses generally depends upon the severity of the injury and differs considerably between hormones, for reasons that are not understood. The only endocrine changes consistently seen at later times after trauma are an increase in insulin secretion, which supersedes the initial suppression, and decreases in the concentrations of T3 and gonadal steroids. Some of the changes in steroid, thyroid and pancreatic hormones differ temporally or even qualitatively from those of their usual stimuli and are unexplained. The initial neuroendocrine response to injury can be construed as playing a defensive role, but the function of the later changes is not understood; it seems likely that they are adaptive in nature, but the scope for therapeutic intervention remains unclear.
 ...
PMID:The neuroendocrinology of physical injury. 332 96

Vasoactive intestinal peptide (VIP)-immunoreactive nerve fibers have been demonstrated in the rat adrenal cortex in close association with zona glomerulosa cells, suggesting neural regulation of adrenocortical cell function (5). The present studies were undertaken to study the possible role of VIP in the regulation of steroid hormone secretion from the outer zones of the normal rat adrenal cortex. Capsule-glomerulosa preparations, consisting of the capsule, zona glomerulosa, and a small but variable portion of the zona fasciculata, were perifused in vitro. To assess the secretory responsiveness of the capsule-glomerulosa preparation, aldosterone and corticosterone release were measured after stimulation with ACTH and angiotensin II. ACTH (10(-12)-10(-8) M) stimulated dose-dependent increases in aldosterone secretion (1.9- to 36.9-fold increases over basal values) and corticosterone secretion (1.4- to 14.0-fold increases over basal values). Angiotensin II (10(-8)-10(-5) M) stimulated dose-dependent increases in aldosterone secretion (1.6- to 8.8-fold increases over basal values). VIP (10(-6)-10(-4) M) stimulated dose-dependent increases in both aldosterone (1.7- to 41.0-fold) and corticosterone secretion (1.8- to 5.3-fold). However, glucagon and (N-Ac-Tyr1-D-Phe2)GRF-(1-29)NH2, peptides structurally related to VIP, stimulated neither aldosterone nor corticosterone secretion, indicating that VIP effects are likely to be specific for this peptide. It is noteworthy that in this preparation, the stimulation of corticosteroid secretion by VIP at 10(-5) and 10(-4) M was comparable to those by 10(-6) M angiotensin II and 10(-9) M ACTH, respectively. These results support the hypothesis that the VIP innervation of the adrenal cortex may contribute directly to the regulation of adrenal steroidogenesis.
 ...
PMID:Vasoactive intestinal peptide stimulates adrenal aldosterone and corticosterone secretion. 335 77

In order to evaluate the pathogenesis of the systemic hyperdynamic circulation in portal hypertension, serum concentration of eight kinds of hormones including glucagon (Glu), aldosterone (Ald), renin (Ren), and epinephrine (Adr), and the hemodynamic parameters were measured in a series of 30 patients, of whom 23 were patients with liver cirrhosis, 3 were with Banti's disease, 2 with chronic active hepatitis, and 2 with pre-cirrhotic change. The average cardiac index was 4.6l/min, m2, with normal PCWP of 6.7 mmHg. CI. and SVR. showed significant inverse correlation of r = -0.767 (p less than 0.01), however, PCWP and CI did not have any significant correlation. Average serum concentrations of Glu, Ald, and Ren were 160 pg/ml, 139 pg/ml, and 5.4 ng/ml, respectively, all of which were increased up to 2.5 times above the normal values. Adr, norepinephrine, cortisol, estrone and estradiol were within normal limits. Of the eight hormones being measured, only Glu had significant correlation with both liver function tests and the cardiac index (r = 0.479, p less than 0.05). Neither Ald nor Adr had significant correlation with hemodynamic parameters.
 ...
PMID:[Systemic hyperdynamic circulation and serum hormone concentrations in portal hypertension]. 352 13

The stress response in humans commonly includes elevations in plasma concentrations of glucocorticoids, catecholamines, glucagon, growth hormone, aldosterone, and renin, resulting in alterations in the metabolism of glucose and other energy substrates, and in increased sodium and water retention. In severe illness, triiodothyronine and sometimes thyroxine are decreased without evidence of clinical hypothyroidism. Antidiuretic hormone may be elevated in bacterial meningitis and other central nervous system disorders, as well as in acute asthma, chronic ventilator therapy, pneumothorax, atelectasis, and postoperatively. Increased ADH concentration can lead to significant hypoosmolality and hyponatremia with adverse effects on the patient. In the setting of severe intracerebral insults, ADH may be inappropriately low, resulting in diabetes insipidus. Insulin concentrations may be inappropriately low for serum glucose concentration, or insulin may have diminished receptor responsiveness in seriously stressed patients. Either situation leads to hyperglycemia. Disturbances in calcium, phosphorus, and magnesium homeostasis may occur relatively frequently in the critically ill patient in response to therapeutic interventions, or illness-induced altered metabolism. It is not always clear when an altered metabolic or hormonal state is an appropriate response to a stress, or represents decompensation of the body's mechanisms for coping with that stress. It is important, however to recognize the common responses of the organism to severe illness, and to monitor for treatable abnormalities which occur.
 ...
PMID:Endocrine manifestations of critical illness in the child. 354 20

The effect of peroral administration of xylitol (5% or 20% in food) on adrenal function was investigated in thirty-five Long-Evans male rats. The control rats were fed either a non-substituted stock diet or a 20% glucose diet. Glucose elevated and 20% xylitol reduced the growth of the rats (P less than 0.001), but 5% xylitol had no effect on the body weight. The concentrations of serum glucose and lactic acid decreased in rats fed 20% and 5% xylitol, respectively, but those of insulin, glucagon, corticosterone and aldosterone were not affected. In the adrenal glands, 20% xylitol loading was associated with increased epinephrine (P less than 0.05) and norepinephrine (P less than 0.001), but with decreased aldosterone (P less than 0.001) concentrations. The weights and histological picture of adrenal glands were normal. The urinary pH of xylitol-fed rats decreased significantly (P less than 0.01). Although peroral xylitol affected the levels of aldosterone and catecholamines, a normal glucocorticoid metabolism was permitted. The reduced aldosterone levels were regarded as secondary reactions, possibly resulting from alterations in electrolyte and/or acid-base balance. The increased catecholamine synthesis may be associated with the promoting effect of xylitol on intestinal calcium absorption.
 ...
PMID:Adrenal function of the rat in relation to peroral administration of xylitol: depression of aldosterone. 363 Jul 41

In a randomised, double-blind, cross over trial, 25 patients with mild to moderate primary hypertension were given nifedipine 20-40 mg twice daily and labetalol 200-400 mg twice daily after a 4 week period on placebo, followed by the two drugs in combination. The BP during placebo therapy was 164/108 mmHg supine and 159/110 mmHg standing. After monotherapy with nifedipine for 6 weeks the supine BP was reduced by 18/13 mmHg and the standing BP by 20/12 mmHg; with labetalol the corresponding figures were 26/15 mmHg and 28/21 mmHg, respectively. The combined therapy induced a larger fall in BP, by 36/22 mmHg supine and by 39/24 mmHg standing; in 21 of 23 patients the BP became normal. The heart rate (HR) decreased during labetalol treatment alone and on the combined therapy. With nifedipine alone, the HR was unchanged in the supine position and increased on standing. Nifedipine increased plasma renin activity (PRA) and urinary aldosterone excretion (uA), whereas labetalol reduced both. During combination therapy, PRA and uA remained unchanged. There was a slight fall in HDL-cholesterol during treatment with labetalol alone and in combination with nifedipine. The fasting blood glucose increased slightly during treatment with each of the drugs, but neither caused a change in the concentrations of glycosylated haemoglobin A1, serum insulin, C-peptide, or plasma glucagon. Adverse effects as a rule were well tolerated and were related to the pharmacological effects of the drugs. Only 2 patients left the trial, both during labetalol treatment.
 ...
PMID:Antihypertensive and metabolic effects of nifedipine and labetalol alone and in combination in primary hypertension. 390 21

The aging kidney suffers reduction both in mass and in glomerular filtration rate. These changes may be totally or partially due to atherosclerosis and hypertension, which reduce renal blood flow. Superimposed on these processes, and perhaps responsible for primary loss of renal mass irrespective of renal vascular disease, is glomerular damage and involution that is a consequence of adaptive increases in glomerular perfusion pressure that occurs as the number of nephrons decline with age. The data available at this time do not allow us to distinguish between these two potential mechanisms of renal senescence. The decline in GFR is in turn responsible for reduced renal acidification and the reduced renal clearance of drugs that are normally removed by the kidney. Certain renal functions, however, are depressed to a greater extent than is GFR. Both the ability to maximally dilute the urine and to maximally concentrate it are controlled by serum ADH concentrations and by the action of that hormone on the collecting duct. Aged rats do not maximally secrete ADH under conditions of dehydration and the effect of ADH on the kidney is also attenuated. Elderly humans also cannot maximally suppress ADH secretion when serum osmolality is reduced. Likewise, the renin-angiotensin-aldosterone axis is poorly responsive to volume depletion in aging subjects. As a result, elderly individuals cannot maximally retain sodium under conditions of plasma volume contraction out of proportion to reduction in GFR. The kidney is the site of vitamin D1 hydroxylation. Hydroxylation of vitamin D is reduced out of proportion to any reduction in GFR in the rat. There are no data as yet available on the effect of aging and the production of erythropoietin, a principal regulator of red blood cell mass. Neither are there data available on changes that might occur with advancing age in the ability of the aging kidney to metabolize various hormones, such as parathyroid hormone, glucagon, and insulin. The mechanisms and the full biochemical and physiologic consequences of renal senescence remain to be fully elucidated.
 ...
PMID:The aging kidney. 391

A study was made of change in hormone secretion in 243 patients with alimentary-constitutional and hypothalamic obesity. Activation of the somatostatin mechanism, a decrease in somatotropic and thyrotropic function of the hypophysis, an increment of corticotropin, beta-lipotropin and vasopressin levels in the blood, disturbance of circadian fluctuations of hormone secretion, an increase in insulin and C-peptide secretion, a decrease in glucagon secretion and triiodothyronine and cortisol levels in the blood, activation of the renin-aldosterone system and cortisol secretion rate were equally expressed both in alimentary-constitutional and primary hypothalamic obesity. The central mechanisms of the regulation of endocrine functions were incorporated in a pathological process even in alimentary-constitutional obesity. Disorders of the hypothalamic regulation lay in the basis of both types of obesity.
 ...
PMID:[Comparative evaluation of the hormonal changes in alimentaro-constitutional and hypothalamic obesity]. 395 72

Low serum, cerebrospinal fluid, erythrocyte, muscle and bone Mg concentrations have been found in liver cirrhosis, indicating a Mg deficiency. Decreased intake, fat malabsorption, renal tubular acidosis and increased serum levels of aldosterone, growth hormone and glucagon could be the causative factors.
 ...
PMID:Magnesium and liver cirrhosis: a hypothesis. 403 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>