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

Studies in humans have shown that cortisol administration (200 mg/day) increases cardiac output, renal vascular resistance, glomerular filtration rate, plasma volume, extracellular fluid volume, exchangeable sodium, plasma glucose, insulin, renin substrate and atrial natriuretic peptide concentrations as well as urinary kallikrein excretion. Cortisol treatment decreases renin and angiotensin II concentrations while catecholamines and vasopressin are decreased or unchanged. We have clear evidence from a number of studies that cortisol-induced hypertension is modulated by, but not dependent on, exogenous sodium. The increase in cardiac output normally seen with cortisol administration is not essential for the blood pressure rise. The role of the increase in renal vascular resistance in the genesis of the hypertension is unclear. Studies using measurements of noradrenaline spillover and assessment of reflex function have not shown any increase in sympathetic nervous system activity but changes in vascular responsiveness, particularly to phenylnephrine and noradrenaline are marked. Cortisol is known to have a variety of effects on brain, heart, kidneys, blood vessels and body fluid volumes. To what extent the observed changes are epiphenomena, amplifiers or modulators, or are causal is unclear. Cortisol hypertension may reflect a complex interplay of these factors varying with the steroid concentrations achieved, underlying genetic factors and the particular experimental circumstances.
 ...
PMID:Experimental studies on cortisol-induced hypertension in humans. 747 17

The 24-h hormone profiles have been well documented in caucasians living in a temperate climate, but they have never been examined in melanoid subjects under equatorial conditions, with a 12-h light-dark cycle in a hot climate. To establish normal data for this population, blood samples were taken at 10-min intervals over 24 h in five healthy young melanoids living in Abidjan (Ivory Coast). Cortisol and thyroid stimulating hormone (TSH) concentrations and plasma renin activity (PRA) were determined by radio-immunoassay and sleep was registered using polysomnography. Data were compared with results obtained in Strasbourg (France) from six healthy aged-matched caucasians. The 24-h profile of cortisol concentration was similar in both groups, with a 2-h phase advance in the melanoids. Nocturnal fluctuations of PRA, strongly linked to the rapid eye movement-non rapid eye movement (REM-NREM) sleep cycles, occurred in both groups, with higher levels in the caucasians in the last 2 h of sleep along with greater amounts of NREM sleep. After an evening increase in TSH, the sleep onset-related decrease seen in the caucasians was not observed in the melanoids. In both groups, increasing concentrations of TSH and cortisol occurred with awakening, decreasing concentrations being observed during slow-wave sleep. As in the caucasians studied in the temperate climates, the melanoid subjects living at the equator showed the same temporal organization of hormone rhythms within the 24-h period and the same relationships between the pulses and specific sleep stages.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Twenty-four-hour profiles and sleep-related variations of cortisol, thyrotropin and plasma renin activity in healthy African melanoids. 760 96

Components of the renin-angiotensin system have been found in a variety of tissues during fetal and postnatal life and appear to be developmentally regulated. We postulated that hormonal changes associated with parturition participate in the regulation of renin, angiotensinogen (Ao) and angiotensin type 1 receptor (AT1) gene expression. Cortisol, which increases rapidly in fetal blood before delivery, has been shown to influence the maturation of various systems in the developing fetus. To test the hypothesis that an increase in cortisol regulates fetal renin. Ao, and AT1 mRNA gene expression, we used Northern blot analysis to study the effects of an intraperitoneal infusion of cortisol (3 mg/h, 1 mL/h) for 48 h on the expression of these genes in twin ovine fetuses (n = 10 pairs) at 130-d gestation (term 145 d); one twin in each pair served as a saline-treated control (0.9% NaCl, 1 mL/h). Plasma cortisol levels were significantly higher in cortisol-treated fetuses (113 +/- 23 nmol/dL) than in twin controls (4.6 +/- 0.8 nmol/dL). Cortisol infusion significantly decreased AT1 receptor mRNA levels in kidney and liver by 24 +/- 7% and 27 +/- 8%, respectively, when compared with controls (p < 0.05), whereas in contrast, increased mRNA levels (p < 0.05) in heart right atrium (91 +/- 23%) and ventricle (59 +/- 20%). Renin mRNA levels decreased in renal cortex by 77 +/- 13% (p < 0.05) in cortisol-treated animals compared with controls. Hepatic Ao mRNA levels decreased by 15 +/- 5% in response to cortisol (p < 0.05), whereas no significant effect was seen on renal Ao gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Effect of cortisol on gene expression of the renin-angiotensin system in fetal sheep. 765 58

Preeclampsia is accompanied by amplification of the sodium retention that is a feature of normal pregnancy. Recent evidence suggests that mineralocorticoid receptor activation is increased in preeclampsia, but classic mineralocorticoids (aldosterone, 11-deoxycorticosterone) are not present in excess. Cortisol can act as a mineralocorticoid receptor agonist only when its renal inactivation to cortisone by 11 beta-hydroxy-steroid dehydrogenase is impaired, for example, in congenital enzyme deficiency and after administration of exogenous inhibitors (eg, licorice). Endogenous inhibitors of this enzyme have been detected in human urine and are increased in pregnancy. To establish whether cortisol causes mineralocorticoid excess in hypertensive pregnancy and whether endogenous inhibitors of 11 beta-hydroxysteroid dehydrogenase are responsible, we studied 25 hypertensive pregnant patients (13 with preeclampsia and 12 with gestational hypertension), 16 normotensive pregnant subjects, and 13 nonpregnant control subjects. Concentrations of plasma renin and aldosterone were increased in pregnancy, but less so in hypertensive pregnancy. Plasma potassium and urinary electrolytes were not different between the groups. Plasma cortisol was increased in pregnancy but not different in hypertensive pregnancy, and urinary cortisol, plasma and urinary cortisone, and urinary tetrahydrocortisol and tetrahydrocortisone were not different between the groups. Endogenous inhibitors of 11 beta-hydroxysteroid dehydrogenase were more active in urine from pregnant women but were not increased further in hypertensive pregnancy. There were no differences in these parameters between patients with preeclampsia and gestational hypertension. We conclude that deficient inactivation of cortisol to cortisone does not contribute to the sodium retention of normotensive or hypertensive pregnancy and that endogenous inhibitors of 11 beta-hydroxysteroid dehydrogenase have no evident pathophysiological significance in pregnancy.
 ...
PMID:11 beta-Hydroxysteroid dehydrogenase and its inhibitors in hypertensive pregnancy. 772 7

Plasma 18-oxocortisol (18-oxoF) and 18-hydroxycortisol (18-OH-F) were measured in 47 healthy subjects. Plasma 18-oxoF and 18-OH-F in the early morning were 0.827 +/- 0.04 nmol/l and 3.29 +/- 0.175 nmol/l, respectively. The plasma levels of both steroids correlated with each other and with cortisol, but not with aldosterone. Postural stimulation with or without furosemide administration increased 18-oxoF, 18-OH-F, aldosterone and plasma renin activity (PRA). Two hours after 2 mg of oral dexamethasone administration or after an overnight 2 mg of dexamethasone suppression cortisol, 18-oxoF and 18-OH-F decreased. Cortisol, aldosterone, 18-oxo-F and 18-OH-F increased after the intravenous administration of 250 micrograms of 1-24 ACTH. Changes in plasma 18-oxo-F and 18-OH-F levels correlated with PRA change during the posture studies and correlated with the change of ACTH during the dexamethasone studies. The ratios of post-/pre-test values of the postural stimulation and dexamethasone suppression in 18-oxoF and 18-OH-F were lower than that of aldosterone. Plasma 18-oxoF and 18-OH-F are more dependent on ACTH than on the renin-angiotensin system. The ratio of 18-OH-F/18-oxoF, which is between 4 and 5, remains constant during the various stimulation or suppression maneuvers.
 ...
PMID:Simultaneous measurement of plasma 18-oxocortisol and 18-hydroxycortisol levels in normal man. 803 8

To analyze the status of the renin-angiotensin system in hypertensive transplant recipients on cyclosporine, we prospectively explored 21 cardiac (CTR: 52 +/- 8.2 yr) and 12 liver (LTR: 45 +/- 10 yr) transplant recipients on a normal salt diet with 19 normotensive controls in the same age range. Systolic and diastolic blood pressure was measured in the supine and standing positions. Renal function was assessed by serum creatinine values, and 24-hr urinary sodium and potassium excretion were recorded. Plasma renin activity (PRA), active renin, total renin, angiotensinogen, aldosterone, and cortisol plasma levels were simultaneously determined. Results were expressed as mean +/- SD, and between-group differences were compared using variance analysis. Supine blood pressure (+/- SD) was 158 +/- 15/103 +/- 8.4 in CTR and 155 +/- 21.4/102 +/- 11.7 mmHg in LTR. Serum creatinine was higher in CTR (159 +/- 52 mumol/L) than in LTR (117 +/- 24.7, P < 0.05) and values in both groups were above controls (83 +/- 14.1, P < 0.05). Urinary sodium excretion tended to be lower in transplant recipients (59 +/- 42 mmol/L) for CTR and 44 +/- 36.7 in LTR than in healthy controls (117 +/- 24.7 mmol/L). Supine and upright PRA values tended to be higher in hypertensive transplant recipients than in healthy volunteers, although not significantly. Supine active renin was significantly higher in CTR (47 +/- 42 pg/ml) and in LTR (44 +/- 29.8 pg/ml) than in normal subjects (17 +/- 4.8 pg/ml, P < 0.05). Total renin levels in CTR (supine: 716 +/- 357 pg/ml) and in LTR (supine: 647 +/- 365 pg/ml) were 3- to 4-fold higher than in controls (supine: 207 +/- 69 pg/ml) (P < 0.05), as were inactive renin levels (P < 0.01). Active renin was effectively correlated with PRA (P < 0.001) and with total renin (P < 0.001) in the supine and in the upright position. Plasma aldosterone was almost within the normal range in CTR and in LTR, and it did not correlate with PRA values. Plasma angiotensinogen levels were normal in LTR (1032 +/- 226 ng/ml) but were significantly lower in CTR (938 +/- 216 ng/ml, P < 0.05). Cortisol plasma levels were lower in both CTR (7 +/- 4.4 micrograms/L) and LTR (6 +/- 1.9 micrograms/L) than in healthy controls (11 +/- 4 micrograms/L, P < 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Cyclosporine-induced stimulation of the renin-angiotensin system after liver and heart transplantation. 821 12

There are few data on the hormonal response to operation in the premature infant. Studies examining the response of newborn human infants have been performed on patients beyond the first few days of life, where some adaptation to postnatal life has occurred. This study evaluated the response of the newly born premature primate to surgical stress. Premature baboons (75% gestation) were intubated, mechanically ventilated and underwent thoracotomy at 2 hours of life with exposure of the ductus arteriosus (PDA). In group 1, formalin was infiltrated to keep the ductus patent. In group 2, the PDA was ligated. Controls had no operation. Blood was drawn at 0, 6, 24, 48, 72, and 96 hours of age. Echocardiograms were performed to confirm patency or closure of the ductus and to monitor cardiac function. Epinephrine, norepinephrine, renin, and cortisol levels were measured. Cortisol levels rose in all groups. Operation stimulated a marked increase in catecholamine and renin levels in both operative groups, which was more marked in the group with PDA ligation at 24 hours. These data reflect expected pathophysiology since early PDA ligation exerts additional hemodynamic demand on the heart. In conclusion, the premature primate is able to mount a significant and severity-dependent endocrine response to stress.
 ...
PMID:Hormonal response of the premature primate to operative stress. 833 18

The case is described of a 40-year-old female with severe hypertension and hypokalaemic metabolic alkalosis, due to prolonged liquorice ingestion. The pseudo-aldosterone-like effects of liquorice have always been attributed to glycyrrhizic acid, but its biochemical substrate has remained elusive. It is now known that glycyrrhetenic acid, the hydrolytic metabolite of glycerrhizic acid, is the active component of liquorice which causes inhibition of the peripheral metabolism of cortisol. Cortisol binds with the same affinity as aldosterone to the mineralocorticoid receptor resulting in a hypermineralocorticoid condition. Ingestion of liquorice may therefore result in retention of sodium and water, hypertension, hypokalaemia, alkalosis and suppression of the renin-aldosterone system. The literature on liquorice-induced hypertension is briefly reviewed with emphasis on the biochemical features of this mineralocorticoid excess syndrome.
 ...
PMID:Liquorice-induced hypertension--a new understanding of an old disease: case report and brief review. 854 95

We have assessed the potential for myocardial ischaemia during laparoscopic cholecystectomy in 16 otherwise healthy patients. Continuous ambulatory ECG monitoring was commenced 12 h before operation and continued for 24 h after operation. The neuroendocrine stress response was assessed by measuring plasma concentrations of adrenaline and noradrenaline, human growth hormone, cortisol, renin and aldosterone, and prolactin, at specified times during surgery. Acute ST segment changes in the ECG occurred in only two patients. These episodes were independent of creation of pneumoperitoneum and changes in position. Acute intraoperative increases in MAP were noted during insufflation of carbon dioxide and reverse Trendelenburg positioning (P < 0.05). A four-fold increase in plasma concentrations of renin and aldosterone was noted after pneumoperitoneum and reverse Trendelenburg positioning (P > 0.05). There was a linear correlation between changes in plasma renin and aldosterone concentrations and MAP (r = 0.97 and r = 0.85, respectively). Prolactin concentrations increased four-fold after induction of anaesthesia. Cortisol, HGH, adrenaline and noradrenaline concentrations increased after deflation of the pneumoperitoneum. The time profile-concentration changes of increased MAP and renin-aldosterone suggests a cause-effect relationship. Increased intra-abdominal pressure and reverse Trendelenburg positioning may reduce cardiac output and renal blood flow. The early increase in prolactin concentration was probably secondary to the effect of the opioid fentanyl.
 ...
PMID:Laparoscopic cholecystectomy: haemodynamic and neuroendocrine responses after pneumoperitoneum and changes in position. 901 45

The purpose of this study was to compare, in the same subjects, hormonal responses to 30-min head-up tilt (HUT) and lower body suction (LBNP) of different intensity (24 degrees and 70 degrees, and 15 and 35 mm Hg, respectively). Basal pooled individual data from -10 min (n = 32) were within normal reference limits: norepinephrine (NE) averaged 318 +/- 23 pg/ml; epinephrine, 34.0 +/- 5.5 pg/ml; plasma renin activity (PRA), 0.72 +/- 0.08 ng ATII/ml/h; aldosterone, 164 +/- 20 pg/ml; atrial natriuretic peptide (ANP), 29.9 +/- 2.0 pg/ml; cGMP, 6.29 +/- 0.59 mmol/l; cortisol, 95.7 +/- 5.8 ng/ml; and ACTH, 50.3 +/- 2.6 pg/ml. The low-level stimuli failed to induce consistent changes in hormone levels. From the onset of the stimulus (minute 0) to its termination (minute 30), norepinephrine (NE) increased by 101% with LBNP-35, and by 70% with HUT70, respectively. The NE increase with LBNP-35 was higher (p < 0.05) than with HUT70. Epinephrine rose with HUT70 (by 162%) only. PRA increased by 157% with LBNP-35, and by 119% with HUT70, respectively; these responses were not significantly different. Aldosterone rose equally (by 85 and 89%) with LBNP-35 and HUT70 but not with the low-level stimuli. No consistent changes were observed in ANP, c-GMP or ACTH concentrations. Cortisol values fell during the LBNP and HUT24 situations but rose transiently after HUT70. We conclude that the hormones investigated respond differently to head-up posture and lower body suction and in a specific manner. Greater effects of high-level stimuli (HUT70, LBNP-35) were noted as compared to low-level stimuli (HUT24, LBNP-15). The application of combined sets of models stimulating the cardiovascular system may aid in the analysis of responses of hormonal systems in man.
 ...
PMID:Head-up tilt and lower body suction: comparison of hormone responses in healthy men. 908 64


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