Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of dietary changes and plasma aldosterone levels on channel-mediated electrogenic amiloride-sensitive Na+ transport were examined in the distal colon of immature and adult rats. The decrease of the short-circuit current after amiloride addition (ISCamil) was used as a measure of electrogenic Na+ absorption. Plasma aldosterone levels were six to eight times higher between d 15 and 30 than in younger suckling or prepubertal rats. In adult rats, the plasma aldosterone was approximately 30 times lower than in young animals kept on the same standard diet. ISCamil followed the developmental profile of plasma aldosterone. ISCamil increased between d 10 and 20, reached a plateau between d 20 and 25, then decreased and entirely disappeared after d 30. ISCamil was zero in adult distal colon but was induced if dietary Na+ intake decreased below 100 mumol Na+/(100 g body wt.d) and plasma aldosterone increased above 200-300 pg/mL. Adrenalectomy, or high Na+ intake, inhibited ISCamil and significantly depressed plasma aldosterone in 20- and 25-d-old rats. Premature weaning decreased ISCamil without appreciable changes in plasma aldosterone in 18- and 20-d-old rats, prolonged suckling inhibited ISCamil and caused a significant depression of plasma aldosterone. We conclude from these results that the postnatal changes of distal colonic Na+ transport are regulated predominantly by circulating aldosterone and dietary Na+ intake.
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PMID:Regulation of amiloride-sensitive Na+ transport in immature rat distal colon by aldosterone. 749 59

We recently showed that patients with compensated cirrhosis can dispose of their fluid overload while reclining. In contrast, patients with ascites fail to develop supine-induced natriuresis. To assess the effect of reclining on renal sodium handling in patients with advanced cirrhosis and the mechanisms blunting natriuresis in this situation, renal function and plasma concentrations of atrial natriuretic factor, aldosterone and norepinephrine were evaluated in 10 nonazotemic patients with cirrhosis and ascites and 10 healthy controls standing for 2 h and reclining for 2 h. While standing, all patients showed marked sodium retention and significantly elevated plasma atrial natriuretic factor levels, aldosterone and norepinephrine. Glomerular filtration rate did not differ from healthy controls. The reclining increased renal sodium excretion in both groups, but this change was far less marked in patients; natriuresis only rose to the control range in two of them. An increase in atrial natriuretic factor and a depression of plasma aldosterone and norepinephrine was seen in both controls and patients. In the latter, despite the greater change in atrial natriuretic factor and aldosterone, the aldosterone to atrial natriuretic factor ratio, which was inversely correlated with natriuresis during both standing and reclining remained significantly elevated. In the two patients who achieved normal natriuresis during reclining, reclining was associated with both the normalization of the aldosterone/atrial natriuretic factor ratio, and with an increase in glomerular filtration rate. The supine-induced increase in atrial natriuretic factor was not only preserved but was even enhanced in cirrhosis with ascites.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Renal sodium handling in cirrhosis with ascites: mechanisms of impaired natriuretic response to reclining. 769 37

To elucidate the significance of long-term administration of dexamethasone in order to differentiate the 4 types of hyperaldosteronism, blood pressure, serum electrolytes, plasma renin activity (PRA) and diurnal rhythm of plasma aldosterone (PAC) were studied before and after long-term dexamethasone (Dex) administration in patients with aldosterone-producing adenoma (APA), idiopathic hyper aldosteronism (IHA), unilateral adrenal hyperplasia (UAH) and Dex suppressible hyperaldosteronism (DSH). The results were as follows: 1) In APA with ACTH-dependent aldosterone secretion, long-term Dex administration induced a significant depression of PAC associated with an elevation in serum potassium (s-K). In almost all patients with APA, the diurnal rhythm of PAC, parallel to that of ACTH, completely disappeared following Dex administration. 2) In most patients with IHA, PAC was mainly influenced by the renin-angiotensin system. Dex did not affected on s-K, but it induced a slight decrease in PAC in some patients with IHA. 3) In UAH having similar pathophysiological findings of the adrenal cortex as IHA, Dex decreased PAC. 4) In DSH, Dex at a dose of 6 mg/day decreased PAC to normal value in association with normalization of blood pressure and s-K. From these results, hyperaldosteronism inducing a decrease in PAC and an increase in s-K by Dex is possibly diagnosed as APA, while the patients with no change of s-K by Dex may be diagnosed as IHA. Even if PAC is suppressed with Dex and ACTH-independent, the hyperaldosteronism may be UAH. It may be possible that factors other than aldosterone are important to induce hypokalemia in patients with IHA. Furthermore, it is suggested that UAH is a precedent pathophysiological condition of aldosterone-producing adenoma in the adrenal cortex. It is concluded that the measurement of s-K and diurnal rhythm of PAC before and after Dex administration are useful for discriminating APA and IHA.
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PMID:[The long-term administration of dexamethasone for the differentiation of the 4 types of hyperaldosteronism]. 775 Jun 27

The effect of a subcutaneous bolus injection of 2 micrograms magnitude of Ac,Tyr1,D-Phe2-GRF(1-29) amide, a specific VIP antagonist (VIP-A), on the hypothalamo-pituitary-adrenocortical (HPA) axis were investigated in both normal and ether- or cold-stressed rats. Blood concentrations of ACTH, aldosterone (ALDO) and corticosterone (B) were measured by specific RIA 1, 2 or 4 h after VIP-A injection. VIP-A administration to normal rats strikingly lowered the plasma concentration of ALDO, without significantly affecting those of ACTH and B. Ether and cold stresses notably raised the blood levels of ACTH, ALDO and B, and these rises lasted unchanged until 4 h. VIP-A did not affect the response of HPA axis to ether stress, but provoked a marked depression of that to cold stress. In light of these findings the following conclusions can be drawn: (i) endogenous VIP does not regulate HPA-axis function under basal conditions, but it plays a pivotal role in the mechanisms involved in the activation of HPA axis induced by cold exposure; and (ii) endogenous VIP exerts a tonic stimulatory action on ALDO secretion, probably by acting directly on the adrenal zona glomerulosa.
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PMID:Evidence that endogenous vasoactive intestinal peptide (VIP) is involved in the regulation of rat pituitary-adrenocortical function: in vivo studies with a VIP antagonist. 786 61

To compare the hemodynamic, antiischemic, metabolic, and neurohumoral effects of intravenous esmolol (beta 1 blocking agent) and gallopamil (verapamil-like calcium channel blocker), 14 patients with angiographically proven CAD and reproducible ST segment depression were studied at rest and during exercise under control conditions and after an intravenous bolus injection of esmolol (0.5 mg/kg/1 min, followed by an infusion with 0.2 mg/kg/min) or gallopamil (0.025 mg/kg/3 min). In contrast to gallopamil, esmolol significantly reduced systolic blood pressure (175.7 vs. 160 mm Hg) and heart rate (107.4 vs. 96.9 min-1) during exercise as well as cardiac output (11.57 vs. 9.38 l/min) and significantly enhanced systemic vascular resistance both at rest (1241 vs. 1479 dynes.s.cm-5) and during exercise (805 vs. 947 dynes.s.cm-5). On the other hand, exercise filling pressures and lactate levels (3.66 vs. 3.05 mmol/l) were significantly reduced by gallopamil only. Thus, the significant improvement of exercise tolerance by both esmolol and gallopamil is based on different mechanisms of action: esmolol improves myocardial ischemia by appreciably reducing myocardial oxygen consumption, whereas gallopamil primarily improves oxygen supply and ventricular performance. Plasma catecholamines, atrial natriuretic factor, and aldosterone levels as well as plasma renin activity were identically influenced by esmolol and gallopamil, respectively. A reflex activation of the sympathetic system did not occur.
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PMID:[Anti-ischemia effects of gallopamil and esmolol in an intra-individual comparison in patients with coronary heart disease]. 791 67

We have previously shown that transdermal nitroglycerin may induce an increase in the activity of the adrenergic and the renin-angiotensin-aldosterone systems (SRAA) in patients with chronic stable angina pectoris (SA); when the activation of these systems is more pronounced, the antianginal effect of this drug seems to be reduced. The aim of this study was to evaluate the antianginal efficacy of transdermal nitroglycerin administration (TTS-NG 10 mg.24 h-1) in combination with an ACE inhibitor without sulphydryl groups (BNZ, benazepril 10 mg b.i.d.) in respect to placebo, or to TTS-NG or BNZ administered as monotherapy. Twenty-four patients (21M, 3F) were admitted to this multicentre, randomized, double-blind, latin square, placebo-controlled study. Patients received all the treatments (placebo, TTS-NG, BNZ and BNZ + TTS-NG) each for one week; at the end of each week patients performed two exercise tests 2 and 22 h post-dosing. Two hours post-dosing, exercise duration at 1 mm ST depression was significantly increased in respect to placebo during TTS-NG (P < 0.05) and TTS-NG + BNZ (P < 0.05) treatments. Two hours post-dosing, exercise duration at peak exercise was also increased in respect to placebo during TTS-NG (P < 0.05) and TTS-NG + BNZ (P < 0.05); 22 h post-dosing the increase in exercise duration was significant only during TTS-NG + BNZ treatment (P < 0.05) in respect to placebo, but not during TTS-NG given alone. Rate-pressure product at 1 mm ST depression was significantly increased 2 h post-dosing during TTS-NG treatment (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of transdermal nitroglycerin in combination with an ACE inhibitor in patients with chronic stable angina pectoris. 813 70

In healthy women we have studied the effects of potassium depletions of different degrees on the generation of some bioregulators of hydro-saline balance. The study has been performed on 20 women in normal potassium balance (N group) and 20 women submitted to potassium depletive treatment by dietary and pharmacological means. On the basis of different patterns of treatment we have obtained three groups i.e. KD1 (n = 8), KD2 (n = 6) and KD3 (n = 6) with potassium cumulative deficit of 160 +/- 43, 198 +/- 22 and 214 +/- 54 mmol, respectively. The renal function was assessed by the clearance method during induced hypotonic polyuria and subsequent moderate antidiuresis induced by low dose infusion of lysine-8-vasopressin. The urinary PGE2, 6-keto-PGF1 (6KPGF) and TxB2 were determined by the RIA method. Moreover, the basal PRA and urinary aldosterone were determined before the renal functional exploration. The data obtained in both KD2 and KD3 groups where renal hypokalemic dysfunctions occurred--indicate that hypokalemia stimulated renin secretion and inhibited the reactivity of renal prostanoid production to the polyuric stimulus. However, in the KD3 group--where the circulating levels of renin, and probably of angiotensin II were the highest--the hypokalemic depression of the synthesis of 6KPGF and TxB2 precursors was attenuated while the synthesis of PGE2 was still inhibited.
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PMID:Studies on renal function in healthy women with different degrees of induced potassium depletion. 1) Hormonal changes relevant to salt and water balance. 815 5

One hundred and one patients, 70 experimental and 31 controls, with a diagnosis of essential hypertension, were examined for the effects of group relaxation training and thermal biofeedback on blood pressure and on other psychophysiologic measures: heart rate, forehead muscle tension, finger temperature, depression, anxiety, plasma aldosterone, plasma renin activity, and plasma and urinary cortisol. Eighty percent of the participants were medicated. Treatment yielded a short-term success rate, defined as a decrease in mean arterial pressure of 5 mm Hg, of 49% in the experimental group. Other significant short-term changes included a reduction of forehead muscle tension, state anxiety, plasma aldosterone, and increased finger temperature. Follow-up measurements were made approximately 10 months after treatment in 36 patients, 51% of the treatment completers. Twenty of the 36 were short-term treatment failures, while 16 were treatment succeeders. Thirty-seven percent of the short-term succeeders continued to meet blood pressure criterion at follow-up. In short-term succeeders, continued practice of relaxation may influence long-term maintenance of decreased blood pressure. It is suggested that group relaxation training can be beneficial for short-term and long-term adjunctive treatment of essential hypertension in selected individuals.
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PMID:Effects of group relaxation training and thermal biofeedback on blood pressure and related physiological and psychological variables in essential hypertension. 816 64

The role of the renin-angiotensin system in renal hypokalaemic dysfunction has been investigated by evaluating the effects of the angiotensin (AT)-converting enzyme inhibition by enalapril. Healthy women were studied either in normal potassium balance (N3, n = 6) or moderate potassium depletion (KD3, n = 6). Potassium depletion (KD) was induced by low potassium dietary intake (greater than or equal to 10 mmol per day) and natriuretic treatment associated with replacement of net NaCl and water losses; the cumulative potassium deficit achieved was 214 +/- 54 mmol. The renal function and the urinary excretions of some prostanoids (PGE2, 6-keto-PGF1 alpha, TxB2) were evaluated during hypotonic polyuria (oral water load) and subsequent moderate antidiuresis (lysine-8-vasopressin (LVP) low-dose infusion). Paired studies were performed in absence (control) and presence of enalapril. Basal plasma renin activity (PRA) and urinary aldosterone excretion were determined before the water load of control studies. Renal dysfunction typical of chronic KD occurred in the KD3 group, i.e. increase in PRA, decrease in creatinine clearance, depression of the diuretic response to water load, inhibition of distal fractional chloride reabsorption, and blunted efficacy of LVP in increasing the urinary solute concentration. The urinary prostanoid excretions were reduced. Basal urinary aldosterone excretion was not changed significantly. In KD3 group enalapril decreased mean arterial pressure (MAP), increased the plasma potassium concentration, improved the diuretic response to water load and corrected the impairment of the distal fractional chloride reabsorption. Despite the decrease in MAP enalapril did not affect significantly the creatinine clearance. Neither urinary prostanoid excretions nor the renal response to LVP were affected by the drug. The data suggest that in KD the increased activity of the renin-angiotensin system affected the renal function both through direct effects and through effects dependent on the angiotensin-supported secretions of aldosterone and probably of vasopressin. Finally, by comparing the effects of enalapril and indomethacin in experimental groups with an equivalent degree of KD, evidence is provided in favour of the interaction between renin-angiotensin and prostanoid systems in controlling the glomerular filtration rate and the salt and water handling by renal tubules.
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PMID:Effects of angiotensin-converting enzyme inhibition on renal dysfunction induced by moderate potassium depletion in healthy women. 820 52

Literature on case reports, clinical studies and biochemical mechanisms of the sweet-tasting compound glycyrrhizic acid in liquorice was critically reviewed to provide a safety assessment of its presence in liquorice sweets. A high intake of liquorice can cause hypermineralocorticoidism with sodium retention and potassium loss, oedema, increased blood pressure and depression of the renin-angiotensin-aldosterone system. As a consequence, a number of other clinical symptoms have also been observed. Glycyrrhizic acid is hydrolysed in the intestine to the pharmacologically active compound glycyrrhetic acid, which inhibits the enzyme 11 beta-hydroxysteroid dehydrogenase (in the direction of cortisol to cortisone) as well as some other enzymes involved in the metabolism of corticosteroids. Inhibition of 11 beta-hydroxysteroid dehydrogenase leads to increased cortisol levels in the kidneys and in other mineralocorticoid-selective tissues. Since cortisol, which occurs in much larger amounts than aldosterone, binds with the same affinity as aldosterone to the mineralocorticoid receptor, the result is a hypermineralocorticoid effect of cortisol. The inhibitory effect on 11 beta-hydroxysteroid dehydrogenase is reversible; however, the compensatory physiological mechanisms following hypermineralocorticoidism (e.g. depression of the renin-angiotensin system) may last several months. It is not possible, on the basis of existing data, to determine precisely the minimum level of glycyrrhizic acid required to produce the described symptoms. There is apparently a great individual variation in the susceptibility to glycyrrhizic acid. In the most sensitive individuals a regular daily intake of no more than about 100 mg glycyrrhizic acid, which corresponds to 50 g liquorice sweets (assuming a content of 0.2% glycyrrhizic acid), seems to be enough to produce adverse effects. Most individuals who consume 400 mg glycyrrhizic acid daily experience adverse effects. Considering that a regular intake of 100 mg glycyrrhizic acid/day is the lowest-observed-adverse-effect level and using a safety factor of 10, a daily intake of 10 mg glycyrrhizic acid would represent a safe dose for most healthy adults. A daily intake of 1-10 mg glycyrrhizic acid/person has been estimated for several countries. However, an uneven consumption pattern suggests that a considerable number of individuals who consume large amounts of liquorice sweets are exposed to the risk of developing adverse effects.
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PMID:Glycyrrhizic acid in liquorice--evaluation of health hazard. 838 90


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