Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.15 (renin)
 35,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of partial (50 ml/min/kg) left heart bypass (LHBP) on renal function, plasma renin activity (PRA), aldosterone, arginine vasopressin and atrial natriuretic peptide (ANP) response was studied in ten anesthetized, open-chested mongrel dogs (weight 23-50 kg) over a period of 6 h. Standard equipment with systemic heparinization (control), initially 300 IU/kg, was employed in five dogs, and heparin-coated equipment without additional heparin in the other five (heparin coated). Urine was continuously collected through a transurethral catheter. Urine samples and pulmonary artery blood samples for hormonal assays were taken at preset intervals before and during LHBP. The results in each group were summarized as median (25th-75th) and compared using the Mann-Whitney U test. In the control group higher blood loss required higher volume substitution. Urine output was maintained in heparin coated and slightly decreased at 3-4 h in control LHBP. Creatinine clearance at 3-5 h and free-water clearance at 3-6 h were significantly higher with heparin-coated LHBP. PRA, aldosterone and vasopressin peaked at 1-2 h of LHBP similarly in both groups, not exceeding the values before perfusion. PRA and aldosterone response was sustained during 6 h and the percentage changes corrected for hemodilution indicated a stronger response with standard equipment. Vasopressin concentrations were slightly but significantly higher in the control group at 1 and 6 h of perfusion. Corrected for hemodilution, vasopressin percentage changes were not different in the two groups. ANP, despite atrial unloading, rose similarly in both groups. There was a tendency to poorly sustained ANP response (control greater than heparin-coated) after 6 h of perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Heparin-coated left heart bypass: renal function and hormonal response. 183 57

Endothelin has been shown to affect a broad range of renal functions, including rat inner medullary collecting duct Na/K ATPase activity, renin release, renal blood flow, and glomerular filtration rate. The source of endothelin in the kidney has been assumed to be endothelial cells. However, the inner medulla contains the highest concentration of immunoreactive endothelin in the kidney. Additionally, MDCK cells, a distal tubule-like cell line, synthesize endothelin. In order to determine if primary renal tubule cells release endothelin, supernatants collected from rat inner medullary collecting duct cells in culture were tested for endothelin-1 detected by specific radioimmunoassay. Inner medullary collecting duct cells produced endothelin-1 in a time-dependent manner, releasing 1,016.7 +/- 60.1 pg of endothelin-1 per mg/cell protein/24 h. Inner medullary collecting duct cells expressed a 2.2-kilobase mRNA on blot hybridization with rat prepro endothelin-1 cDNA. Vasopressin, thrombin, bradykinin, and epinephrine did not affect endothelin-1 release. These data demonstrate endothelin-1 production by inner medullary collecting duct cells and suggest a possible autocrine role for the peptide.
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PMID:Endothelin synthesis by rat inner medullary collecting duct cells. 195 27

Reduced homeostatic capacity is typical of the aging process and is particularly apparent in changes in the neuroendocrine control of cardiovascular homeostasis. Not only is there reduced beta-adrenoceptor responsiveness, but reduced baroreflex function also occurs with age. These result in increased sensitivity to the therapeutic and postural hypotensive effects of diuretics and vasodilators. Increased total body sodium and reduced activity of the renin-angiotensin-aldosterone system may also contribute to the therapeutic effect of diuretics and salt restriction in elderly hypertensives. In addition, atrial natriuretic peptide levels are increased in the elderly and may in part be responsible for the suppressed renin and aldosterone levels found in older groups. Vasopressin secretion and thirst are also disturbed with age, and may act in concert with declining renal function to predispose the elderly to disturbances of water balance. An understanding of these neuroendocrine changes with age is important to maximize therapeutic benefit and to minimize adverse effects in the treatment of hypertension in the elderly.
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PMID:Neuroendocrine mechanisms and cardiovascular homeostasis in the elderly. 200 44

The treatment of status asthmaticus is one of the most important factors in controlling the patient with asthma attacks. We have studied hormone changes in status asthmaticus and considered what is the best treatment in the asthma attack condition in children. Antidiuretic hormone (ADH), renin activity, and aldosterone activity are elevated in severe asthma attack conditions, and these high levels are correlated with high levels in Wood's clinical score. It is theoretical that patients with dehydration and respiratory failure show such elevation in hormones, and it is well known that under such conditions beta 2-stimulant enhances renin production. From our study, it is concluded that beta 2-stimulant subcutaneous injection must be considered in status asthmaticus. In children, aminophylline i.v. drip therapy may be one of the best treatments in status asthmaticus.
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PMID:Treatment of status asthmaticus--hormone changes before and after aminophylline i.v. drip therapy. 211 75

Vasopressin, the renin-angiotensin system and atrial natriuretic factor (ANF) interact in regulating blood pressure. While the vasoconstrictor effect of vasopressin and the renin-angiotensin system is well documented, the direct vascular effect of ANF is unclear. We studied in anaesthetized dogs the coronary vascular effects of agonists and antagonists of vasopressin and the renin-angiotensin system under control and ischaemic conditions, respectively. In addition, the action of ANF and its relationship to the renin-angiotensin system was analysed. A coronary artery was cannulated and perfused by a bypass system from the femoral arteries of the same animal. Coronary vasoconstriction by vasopressin was potentiated when myocardial ischaemia was induced by lowering coronary perfusion pressure while coronary constriction by angiotension I and II was mitigated. A vasopressin receptor blocker slightly reduced coronary blood flow at high doses (intrinsic activity) while the angiotensin II receptor blocker increased coronary flow in myocardial ischaemia. ANF effects were ambiguous at lower doses (1 ng (kg)-1 i.c.) with coronary constriction in 79% of dogs. At higher doses (1 microgram kg-1) ANF consistently induced coronary dilation. The angiotensin II receptor blocker saralasin significantly reduced this coronary dilator effect of ANF. Thus, in conclusion, a vasoconstrictor effect of endogenous vasopressin could not be shown by this study. In contrast, endogenous angiotensin II might participate in control of coronary blood flow during myocardial ischaemia. The coronary dilator effect of ANF at least in part appears to be due to interference with the renin-angiotensin system.
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PMID:Coronary arteriolar vasoconstriction in myocardial ischaemia. Vasopressin, renin-angiotensin system and ANF. 214 82

To evaluate whether, and to what extent, release of endogenous vasopressin supports blood pressure when efferent sympathetic drive is blocked by epidural anesthesia, the authors studied the effects of high epidural anesthesia alone and when vasopressin was prevented from acting at its vascular (V1)-receptor in six awake, trained, unsedated dogs. On different days, the same dose of 0.5% bupivacaine (8-13 ml) was injected epidurally in a randomized fashion either in the presence or absence of (V1)-vasopressin receptor blockade, and the effects were evaluated on cardiovascular (arterial blood pressure, heart rate) and respiratory (blood gases, oxygen consumption) variables, and on plasma concentrations of vasopressin and renin. Results were also contrasted to those obtained after epidural injection of saline alone (placebo) in the same dogs. When endogenous vasopressin was prevented from acting by intravenous pretreatment with a specific V1-receptor antagonist (beta-mercapto-beta, beta-cyclopenta-methylene-propionyl-O-Me-Tyr-Arg-Vasopressin), epidural anesthesia resulted in a rapid and sustained 35% decrease in mean arterial blood pressure from 92 mmHg +/- 5 SE to 60 mmHg +/- 4. In contrast, only a 14% decrease in mean blood pressure from 92 mmHg +/- 5 to 79 mm Hg +/- 6 was noted after epidural anesthesia alone. This difference between groups was statistically significant (P = 0.0001). The V1-receptor blockade alone had no detectable effect. Vasopressin plasma concentrations significantly increased from 3.4 +/- 0.3 pg.ml-1 to 16.2 +/- 3.2 pg.ml-1 after epidural anesthesia but did not change after epidural saline.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Endogenous vasopressin supports blood pressure and prevents severe hypotension during epidural anesthesia in conscious dogs. 200 Oct 46

The concentrations of aldosterone, vasopressin and plasma renin activity were measured in cord blood and on days 1, 3 and 5 of life in 71 newborn infants from the risk group at the development of critical conditions. Vasopressin was discovered to play a substantial role in the development of critical conditions. The lack of a considerable vasopressin ejection in response to a delivery trouble and the growth of its concentration by day 5 of life are prognostically unfavourable. Hyperactivity of the renin-aldosterone system determines the newborns' proneness to liquid and sodium retention.
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PMID:[Clinical value of determining the levels of renin, aldosterone and vasopressin in newborn infants in critical conditions]. 228 86

Water movements across the rumen wall were studied during rehydration in four fistulated sheep. The animals were dehydrated for 48 h which increased total plasma protein, plasma osmolality, plasma Na+, arginine vasopressin and plasma renin activity. Two series of experiments were performed: Expt I with no food available during rehydration, and Expt II where the animals were fed hay. On the rehydration day, a fluid marker (cobalt-EDTA) was administered into the rumen. To avoid water outflow from the rumen a stopper was inserted into the reticulo-omasal orifice. When the animals were provided with water they immediately drank 9 l. The water offered contained the same marker concentration (Co2+) as in the rumen liquid. In Expt I, Co2+ concentration increased after drinking, and remained elevated until the stopper was removed. The highest value was obtained after 20 min, and this corresponded to at least a 11 water absorption in individual animals. In Expt II, the sheep immediately started to eat following drinking and the inflow of saliva caused a dilution of the marker. Plasma osmolality and Na+ concentration decreased in both experiments indicating that water absorption occurred in both experiments. Removal of the stopper did not cause any significant changes in the parameters measured. Vasopressin concentration fell immediately on the sight of water, and then continued to decrease. It is concluded that in the sheep, voluntary drinking is followed by an immediate and substantial absorption of water from the rumen.
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PMID:Fluid absorption from the rumen during rehydration in sheep. 231 May 59

The aim of this study was to assess the hormonal alterations that may mediate the systemic hypertension that develops in patients during the perioperative period of orthotopic liver transplantation. We studied nine pediatric patients without previous hypertension or renal disease during six time points, starting before transplantation and ending at 48 hours after surgery. Hypertension developed in all patients in association with central venous pressures less than 10 mm Hg. Free water clearance was negative in all nine patients. Vasopressin levels increased intraoperatively but fell as hypertension developed. Atrial natriuretic factor levels increased as systemic blood pressure rose. A high level of plasma renin activity was observed in four patients with renal insufficiency. In six patients, postoperative 24-hour urinary norepinephrine excretion was within the normal age-adjusted range. These findings suggest that the combination of cyclosporine, corticosteroids, and, in some patients, an elevated plasma renin activity prevents the kidney from responding to the acute volume and salt overload with an appropriate diuresis and natriuresis, thus leading to systemic hypertension. The treatment of hypertension after liver transplantation may include salt restriction, diuretics, and, in those patients with a low creatinine excretion index, angiotensin coverting enzyme inhibitors.
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PMID:Mechanisms of hypertension during and after orthotopic liver transplantation in children. 252 74

The objective of this study was to determine the effects of transient aortic valve occlusion (balloon valvuloplasty) on vasoactive hormones in patients with heart failure. Plasma atrial natriuretic peptide, vasopressin, aldosterone, adrenocorticotropic hormone (ACTH), and plasma renin activity were measured before, immediately after, and 30 minutes and 18 to 24 hours following balloon inflation in 18 patients. Mean right atrial and pulmonary wedge pressures were 6 and 18 mm Hg before inflations, respectively, and were unchanged after balloon inflations (5 and 13 mm Hg, respectively). Systemic systolic/diastolic pressures were 139 +/- 8/65 +/- 4 mm Hg before occlusion, decreased to 47 +/- 5/34 +/- 3 mm Hg during occlusion, and returned to baseline after occlusions. Baseline atrial natriuretic peptide levels were 267 +/- 43 pg/ml and increased to 513 +/- 71 pg/ml after balloon inflations. Vasopressin levels before occlusion were 9.1 +/- 2.2 pg/ml and increased to 21.4 +/- 4.8 pg/ml after balloon inflations. Plasma renin activity was 5.4 +/- 1.4 ng/ml/hr before inflations and was not significantly changed after balloon inflations. No clinically significant changes in plasma sodium, potassium, creatinine, and osmolality were observed after the procedure. Aldosterone increased from 23 +/- 4 to 40 +/- 7 ng/dl 10 minutes after the last inflation. Plasma ACTH measured in seven patients with increased aldosterone was 28 +/- 8 pg/ml before and increased to 295 +/- 157 pg/ml 10 minutes after balloon inflations. The increases in natriuretic peptide and vasopressin were likely due to elevated intracardiac and decreased arterial pressures, respectively; they persisted in spite of no clinically significant changes in filling pressures 12 to 24 hours after the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Stimulation of atrial natriuretic peptide and vasopressin during percutaneous transluminal aortic valvuloplasty. 254 14


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