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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The amounts of cortisol and testosterone in the plasma or urine of Mongolian gerbils exposed to stress factors or treated subcutaneously with insulin (2 IU), vasopressin (1 IU), ACTH (6 IU) or dexamethasone (50 micrograms) were determined. Increased plasma cortisol was observed in animals stressed by ether anesthesia or immobilisation (1-4 hours), or treated with insulin, vasopressin or ACTH. Cortisol levels were reduced after dexamethasone administration. Plasma testosterone was elevated in animals stressed by ether anesthesia or handling plus seizure; no other treatment altered testosterone levels. An augmented cortisol excretion, which lasted one day, occurred in gerbils immobilised for one as well as for four hours. A much more prolonged stimulation of cortisol excretion, lasting three days, was seen in animals receiving ACTH or dexamethasone plus ACTH. Testosterone excretion was stimulated by ACTH and dexamethasone plus ACTH; it was not influenced by any other treatment. The present study shows that analysis of circulating steroid levels is the only reliable approach to assess the secretory activity of Mongolian gerbil adrenals or testes. In some experimental conditions (e.g. after stressor application or ACTH treatment) cortisol excretion may be used as an index of adrenal secretory function. In contrast, the striking differences between cortisol values present in plasma and urine of peptide-or dexamethasone-treated gerbils indicate that urinary cortisol does not reflect short-term changes of adrenal function. Similarly, the striking differences of testosterone values in plasma and urine indicate that urinary testosterone monitoring cannot be used to determine the secretory activity of gerbil testes.
Exp Clin Endocrinol Diabetes 1996
PMID:Dissociation of plasma and urinary steroid values after application of stressors, insulin, vasopressin, ACTH, or dexamethasone in the Mongolian gerbil. 902 44

Atopic eczema is a chronic inflammatory skin disease which shares some psychological and neuroendocrine disturbances with patients suffering from depression. In view of recent findings of an attenuated response of the hypothalamic-pituitary-adrenal (HPA) system in patients with atopic eczema during a human corticotropin-releasing hormone (hCRH) challenge paradigm fourteen consecutive non-specifically trained in-patients with atopic eczema (8 men, 6 women) and an age-matched control group (8 men, 6 women) performed exhausting incremental graded bicycle exercise to evaluate cortisol, adrenocorticotropin (ACTH), beta-endorphin, epinephrine and norepinephrine releases induced by physical stress. The exercise yielded significant increases in cortisol, ACTH, beta-endorphin, epinephrine and norepinephrine concentrations in both groups. Patients with severe eczema displayed a significantly lower increase in norepinephrine levels when compared with the less affected patient group. In contrast to the challenge with exogenous hCRH no substantial difference in the net responses of ACTH and cortisol could be detected between patients with atopic eczema and controls using the physical stress paradigm. These substantial differences in the net outcome between both challenges may be related to the potential synergizing effects of various neuropeptides, e.g. CRH and vasopressin, when activating the HPA system by challenges at a suprapituitary site which may override subtle disturbances in the responsivity of the HPA system as revealed by CRH challenge alone in patients with atopic eczema.
Exp Clin Endocrinol Diabetes 1997
PMID:Physical stress-induced secretion of adrenal and pituitary hormones in patients with atopic eczema compared with normal controls. 908 93

The majority of cases of central diabetes insipidus are still pathogenetically unclear (idiopathic). Atherosclerotic cholesterol emboli might be partly responsible for some of these idiopathic cases. A 54-year-old woman with known aortic valve stenosis and a history of a transitory ischemic attack presented with sudden-onset polyuria and polydipsia of up to eight l/d, which had started acutely with headaches. She had been treated with lithium for 3 years because of cyclothymic depression. Plasma sodium was in the upper normal range (142-148 mmol/l). Hypertonic saline infusion during lithium therapy revealed a normal threshold of thirst and resetting of vasopressin secretion (osmotic threshold > 300 mosmol/l), whereas vasopressin reserve was normal. Lithium withdrawal led to an even greater delay of vasopressin release upon hypertonic saline infusion (> 310 mosmol/l). Pituitary function tests revealed a normal anterior pituitary function. MR imaging of the hypothalamo-hypophyseal region showed a normal hypothalamic region and a highly intensive neurohypophyseal signal in the T1-weighted image. The patient responded well to desmopressin. We suggest that in this rare case clinical symptoms as well as biochemical findings like impairment of AVP release might be related to a minor structural hypothalamic damage by a vascular lesion, caused, for example, by an atheromatous (cholesterol) embolism in the hypothalamic region responsible for integration of osmoreceptor function and AVP-secretion. The patient's atherosclerosis and aortic stenosis might be responsible for this event.
Exp Clin Endocrinol Diabetes 1997
PMID:Atherosclerosis, aortic stenosis and sudden onset central diabetes insipidus. 928 11

The subcutaneous injection of 5'-bromo-2' deoxyuridine (BrdU) was found to raise the plasma concentrations of ACTH, aldosterone and corticosterone in rats. The aldosterone response was observed at a lower dose of BrdU and lasted for a longer period than those of ACTH and corticosterone (1.25 versus 2.50 mg/100 g body weight; 48 versus 24 h). Corticosterone response to BrdU was partially reversed by the ACTH-receptor antagonist corticotropin-inhibiting peptide (CIP), and aldosterone response by the arginine vasopressin (AVP) V1-receptor antagonist [amino-Pen1, Val4,D-Arg8]-vasopressin (AVP-A). The angiotensin-II (ANG-II)-receptor antagonist [Sar1, Val5, Ala8]-ANG-II (SAR) was ineffective. CIP, AVP-A and SAR, when administered alone, did not alter basal levels of ACTH, aldosterone and corticosterone. In light of these findings the following conclusions can be drawn: (i) BrdU stimulates the hypothalamo-pituitary-adrenal axis in rats, and this effect may influence the results of cell-kinetics studies carried out with the BrdU-labelling technique, especially in those tissue that are highly responsive to glucocorticoids (e.g. pituitary, adrenal and lymphatic tissues); and (ii) different mechanisms underlie the aldosterone and corticosterone secretagogue effects of BrdU, the former being at least in part dependent on the stimulation of AVP release and the latter on the rise in ACTH secretion.
Exp Clin Endocrinol Diabetes 1997
PMID:Different mechanisms mediate the in vivo aldosterone and corticosterone responses to 5-bromo-2'-deoxyuridine in rats. 935 56

Providing glucocorticoids to adrenalectomized (Adx) rats results in downregulation of the vasopressin (AVP)-regulated urea transporter (VRUT) in the renal inner medullary (IM) tip. To examine the physiological relevance of this response, we studied rats with uncontrolled diabetes mellitus induced by streptozotocin (STZ), since these rats have increased corticosterone production and urea excretion. We measured VRUT protein in extracts from the IM tip or base of pair-fed control and diabetic rats by Western analysis using an antibody to rat VRUT. In the IM tip, VRUT was significantly reduced by 39% in diabetic compared with control rats. In the IM base, there was no significant difference between diabetic and control rats. To determine whether the decrease in VRUT in the IM tip was mediated by glucocorticoids, the experiment was repeated using the following three groups of rats: 1) Adx alone, 2) Adx + STZ, and 3) Adx + STZ + replacement with a physiological dose of glucocorticoid. There was no significant difference in VRUT between Adx and Adx + STZ rats. However, VRUT was significantly reduced by 32% in the IM tip of glucocorticoid-treated Adx + STZ rats compared with control Adx + STZ rats. We conclude that glucocorticoids regulate the abundance of VRUT protein independently of insulin in diabetic rats.
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PMID:Glucocorticoids mediate a decrease in AVP-regulated urea transporter in diabetic rat inner medulla. 943 84

While insulin is known to promote vascular smooth muscle (VSM) relaxation, it also enhances endothelin-1 (ET-1) secretion and action in conditions such as NIDDM and hypertension. We examined the effect of insulin pretreatment on intracellular free calcium ([Ca2+]i) responses to ET-1 in cultured aortic smooth muscle cells (ASMCs) isolated from Sprague-Dawley (SD) rats and measured ET(A) receptor characteristics and ET-1-evoked tension responses in aorta obtained from insulin-resistant, hyperinsulinemic Zucker-obese (ZO) and control Zucker-lean (ZL) rats. Pretreatment of rat ASMCs with insulin (10 nmol/l for 24 h) failed to affect basal [Ca2+]i levels but led to a significant increase in peak [Ca2+]i response (1.7-fold; P < 0.01) to ET-1. The responses to IRL-1620 (an ET(B) selective agonist), ANG II, and vasopressin remained unaffected. ET-1-evoked peak [Ca2+]i responses were significantly attenuated by the inclusion of the ET(A) antagonist, BQ123, in both groups. The ET(B) antagonist, BQ788, abolished [Ca2+]i responses to IRL-1620 but failed to affect the exaggerated [Ca2+]i responses to ET-1. Saturation binding studies revealed a twofold increase (P < 0.01) in maximal number of binding sites labeled by 125I-labeled ET-1 in insulin-pretreated cells and no significant differences in sites labeled by 125I-labeled IRL-1620 between control and treatment groups. Northern blot analysis revealed an increase in ET(A) mRNA levels after insulin pretreatment for 20 h, an effect that was blocked by genistein, actinomycin D, and cycloheximide. Maximal tension development to ET-1 was significantly greater (P < 0.01), and microsomal binding studies using [3H]BQ-123 revealed a twofold higher number of ET(A) specific binding sites (P < 0.01) in aorta from ZO rats compared with that of ZL rats. These data suggest that insulin exaggerates ET-1-evoked peak [Ca2+]i responses via increased vascular ET(A) receptor expression, which may contribute to enhanced vasoconstriction observed in hyperinsulinemic states.
Diabetes 1998 Jun
PMID:Insulin increases endothelin-1-evoked intracellular free calcium responses by increased ET(A) receptor expression in rat aortic smooth muscle cells. 960 72

This review focuses on experiments in humans examining the regulation of the hypothalamo-pituitary-adrenal (HPA) system during nocturnal sleep. The HPA system is a most important mediator of the organism's response to stress. The early phase of nocturnal sleep dominated by extended epochs of slow wave sleep (SWS), is the only time of day in which secretory activity of this axis is subject to a pronounced and persistent inhibition resulting in minimum concentrations of ACTH and cortisol. During late sleep predominated by rapid eye movement (REM) sleep. HPA secretory activity reaches a diurnal maximum. Comparison of the response to administration of exogenous secretagogues of ACTH in men during sleep and nocturnal wakefulness indicated that early sleep, and in particular SWS, is associated with an inhibition of pituitary-adrenocortical responsiveness, which is presumably due to hypothalamic secretion of an as yet unknown release inhibiting factor of ACTH. Pituitary-adrenocortical responsiveness during early sleep was disinhibited after canrenoate which is a selective blocker of mineralocorticoid receptors (MR) located primarily in limbic-hippocampal structures. Hippocampal neuronal networks are known to integrate corticosteroid feedback via both, the MR and the classical glucocorticoid receptor (GR). Prevailing MR related activity in this network seems to act as a trigger for the inhibition of the HPA system. During early sleep, the same hippocampal network appears to be concurrently involved in the formation of declarative memory. Activation of GR after administration of dexamethasone completely blocked the formation of declarative memory during early sleep, indicating that the inhibition of HPA secretory activity is a necessary prerequisite for this memory process. Dysfunction of the described neuro-endocrine mode of regulation during early sleep is present in patients with Cushing's disease, in patients with severe depression and in aged humans. All of these groups show insufficient inhibition of HPA secretory activity particular prominent during early sleep, and reduced SWS in concert with impairments of declarative memory function. First clinical trials suggest that this trias of symptoms may benefit from intranasal treatment with neuropeptides like vasopressin and growth hormone releasing hormone.
Exp Clin Endocrinol Diabetes 1998
PMID:Hypothalamus-pituitary-adrenal activity during human sleep: a coordinating role for the limbic hippocampal system. 971 Mar 53

Although it is well known that plasma osmolality and plasma vasopressin (VP) levels in diabetes mellitus are higher than in non-diabetic conditions (and that these levels return to normality with insulin therapy), there are no existing studies which examine for insulin-dependent diabetes, either the persistence of daily rhythmic variations of VP or the relationship between this variation and daily osmotic oscillations. We have therefore examined nycthaemeral variations in both plasma osmolality and plasma VP in normal (C), uncontrolled (D) and controlled insulin-dependent streptozotocin diabetic rats (DI). The uncontrolled streptozotocin treated rats presented, a loss of VP rhythmicity, together with higher values of VP than in both normal and controlled diabetic rats. The VP rhythm, however, could be restored with insulin treatment. Furthermore, the temporal VP/osmolality ratio in uncontrolled diabetic rats is higher than in normal rats, although this ratio does not show the daily rhythmic pattern that is present in both normal and diabetic rats treated with insulin. This may indicate that the lack of rhythmicity in osmotic regulation is responsible for the absence of a circadian rhythm in VP. As a result, we conclude that in uncontrolled diabetic rats, the higher VP levels and the loss of VP circadian rhythmicity could be due to a higher sensitivity in the osmoregulatory system, together with an absence of circadian variation of this system. This circadian variation could be responsible for the plasma VP rhythmicity in both normal and controlled diabetic rats.
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PMID:Variations and interrelation between vasopressin and plasma osmolality in diabetic rats with insulin treatment. 976 68

Wolfram syndrome (WS) is characterized by optic atrophy, insulin-dependent diabetes mellitus, vasopressin (VP)-sensitive diabetes insipidus, and neurosensory hearing loss. Here we report a disturbance in VP precursor processing in the supraoptic and paraventricular nuclei of WS patients. In these patients with diabetes insipidus we could hardly detect any cellular immunoreactivity for processed VP in the supraoptic and paraventricular nuclei. On the other hand, in the paraventricular nucleus a considerable number of cells immunoreactive for the VP precursor were present. In addition, the proprotein convertase PC2 and the molecular chaperone 7B2 were absent. As expression of PC2 and 7B2 was detected in the nearby nucleus basalis of Meynert of one WS patient and in the anterior lobe of the other WS patient, the absence of the two proteins in the paraventricular nucleus was not due to mutations in their genes. These results indicate that in WS patients with diabetes insipidus, not only does VP neuron loss occur in the supraoptic nucleus, but there is also a defect in VP precursor processing.
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PMID:The vasopressin precursor is not processed in the hypothalamus of Wolfram syndrome patients with diabetes insipidus: evidence for the involvement of PC2 and 7B2. 981 87

A patient with a ganglioglioma of the neurohypophysis developed the syndrome of inappropriate antidiuretic hormone secretion (SIADH). We present the case and describe its microscopic and ultrastructural features. Malignant neoplasms were thought to be the main cause of ectopic production of vasopressin. Head trauma, infection, or drugs, however, can also induce hypersecretion of vasopressin. Mechanical compression of the pituitary stalk can lead to an excessive antidiuretic hormone (ADH) release by affecting the inhibitory system. Primary neuroendocrine tumors of the hypothalamic-neurohypophyseal system are extremely rare. We demonstrate the presence of vasopressin in the tumor cells by immunocytochemistry. This represents the first case of SIADH caused by a tumor of the neurohypophysis.
Exp Clin Endocrinol Diabetes 1998
PMID:Ganglioglioma of the neurohypophysis with secretion of vasopressin. 983 10


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