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)

Pharmacological actions of (N-dicyclopropylmethyl)-amino-2-oxazoline (S 3341), an agonist of alpha-2 adrenoceptors, were examined in acute animal studies. In the normotensive anaesthetized dog S 3341 (0.3 mg/kg, i.v.) produced an initial transient increase followed by a marked, prolonged fall in mean arterial pressure (MAP) of 20 mmHg. Central actions of S 3341 were demonstrated by administration of low doses into the vertebral artery of the anaesthetized dog. A rapid and marked fall in MAP resulted which was antagonised by piperoxan. Splanchnic discharges were strongly decreased following S 3341 i.v. administration, suggesting a centrally mediated diminution of sympathetic tone. Peripheral actions of S 3341 were observed in the pithed rat where a dose-dependent increase in MAP was noted which was somewhat antagonised by prazosin and largely by prazosin plus yohimbine. S 3341 reduced hypertension and tachycardia due to stimulation of the sympathetic outflow in the pithed rat, an effect also antagonised by piperoxan. These effects were more marked and prolonged than those of clonidine. S 3341 reduced the tachycardia resulting from stimulation of the cardioaccelerator nerve in the anaesthetized, spinalised and bilateraly vagotomised dog, this effect was reversed by piperoxan. S 3341 did no change the tachycardia induced by noradrenaline or tyramine. Plasma renin activity was significantly decreased after S 3341 treatment in dogs on low normal or high sodium diets. In rats S 3341 decreased the rate of discharge of noradrenergic cells located in the locus coeruleus which are believed to be involved in wake/sleep mechanisms. This depression was 63 times less than that of clonidine. At effective hypotensive doses S 3341 produced no sedation (i.e. loss of righting reflex) in 2 day old chicks. In addition the sedative action of clonidine was inhibited by S 3341 pretreatment. In the mouse tail flick model, the antinociceptive effects of S 3341 were 45 times less than those of clonidine. S 3341, an oxazoline derivative, appears to have haemodynamic effects similar to those of other agonists of central alpha-2 adrenoceptors but with fewer side-effects, and therefore could be of interest an as antihypertensive agent.
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PMID:Pharmacological properties of (N-dicyclopropylmethyl) amino-2-oxazoline (S 3341), an alpha-2 adrenoceptor agonist. 286 74

The conventional "stepped-care" approach to the treatment of hypertension deserves revision. Rational therapy considers a variety of factors to obtain maximum efficacy, safety, tolerability, compliance, and neutralization of neural tone for the prevention of sudden death. The patient's age, gender, race, behavior profile, hemodynamic and neurohumoral status (plasma renin activity, norepinephrine/epinephrine ratio), and quality of life will help determine the choice of antihypertensive agent. Concomitant risk factors (smoking, obesity, diabetes, hypercholesterolemia), the presence of sequelae (left ventricular hypertrophy and/or failure, renal failure), and the existence of other disorders (mitral valve prolapse, depression, anxiety) must also be considered when initiating treatment. In addition, the cost of ancillary expenses (laboratory tests, hospitalizations, and emergency room visits) must be weighed against the potential benefits of therapy. Beta blockers are effective, well tolerated, and versatile for the treatment of concomitant cardiovascular disorders and as behavior modifiers. Calcium channel blockers and angiotensin converting enzyme inhibitors also show promise and merit consideration as therapy for specific groups of hypertensive patients.
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PMID:The 1980s: a patient-specific therapeutic approach in hypertension. 288 36

Animal investigations suggest that the mechanism of the antihypertensive effect of urapidil may be complex. Suggestions have included an alpha 1-blocking action, a weak beta 1-blocking effect, an interaction with a serotonin receptor and a central depression of sympathetic tone. Peripheral alpha 1-blocking activity has been demonstrated in man, and a shift to the right in the dose-response curve to phenylephrine has been found after administration of urapidil, while responses to angiotensin are not affected. Evidence for beta 1-blocking activity is marginal, but urapidil does not inhibit the exercise-induced increase in the heart rate, and there is only some suggestion of a possible inhibition of isoprenaline-induced tachycardia. Possible central activity may be deduced from the observation that while lower single doses reduce blood pressure and increase the heart rate, with higher doses the hypotensive effect continues but the tachycardia no longer occurs. However, lower doses of urapidil lead to an increase in noradrenaline levels, while changes in renin are less constant, but there has been a report that a high dose reduced vanillylmandelic acid excretion. Urapidil reduces peripheral resistance along with arterial pressure, and cardiac output is increased. In spite of a reduced arterial pressure, renal blood flow is maintained, presumably due to dilation of renal vessels. Urapidil is well absorbed orally with a bioavailability of about 70% and a tmax at about 4 h after a sustained release capsule. It is metabolized in the liver with a t1/2 of 4.7 h. In conclusion there is evidence that urapidil is an alpha 1-blocking drug in man.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical pharmacology of urapidil. 290 95

Blood pressure (BP) decreases significantly in patients with immune complex nephritis and hypertension in the course of therapeutic plasma exchange (TPE). To investigate possible underlying mechanisms of this effect, the variations of supine and upright BP and plasma renin activity (PRA) acutely induced by PE (performed by isovolumetric replacement of plasma with 4% albumin in saline solution) were analyzed in six patients. On the average, both supine and upright BP decreased after TPE; however, statistical significance was obtained only for upright systolic BP. Supine and upright PRA did not change significantly, although a clearly blunted response to posture was observed in three patients. The changes of BP induced by TPE were apparently not due to a functional depression of the renin-angiotensin system, since the more marked decrements in BP were observed in the patients with lower basal PRA.
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PMID:Acute effect of plasma exchange on arterial blood pressure and plasma renin activity. 293 91

The atrial natriuretic hormone (ANH) alters cardiovascular function independent of changes in body fluid volume. Most investigators agree that ANH decreases mean arterial pressure (MAP). However, although some investigators have observed a decrease in total peripheral resistance in association with the decrease in MAP, a more frequent observation has been decreased cardiac output (CO). The mechanism whereby ANH decreases CO is unknown, but does not appear to be the result of direct myocardial depression, reductions in intravascular or cardiopulmonary volumes, or venodilation. Alterations in skeletal muscle and splanchnic blood flow have been reported by some but not all investigators. Although increases in renal blood flow have been reported, they are transitory and have not been consistently observed by all researchers. The cardiovascular effects of ANH appear to be influenced not only by the dose, but also by the cardiovascular control mechanisms that operate at the time of ANH administration. Non-renin-dependent hypertensive models exhibit a decrease in MAP associated with decreased CO, whereas in renin-dependent animals this hypotension is associated with a decrease in total peripheral resistance.
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PMID:Hemodynamic effects of atrial natriuretic hormone. 294 23

Although clinically undistinguishable, some authors have found important differences in the counterregulatory response between Biosynthetic Human Insulin (BHI) and Purified Pork Insulin (PPI). To reassess the problem 10 healthy volunteers of both sexes underwent paired iv insulin tolerance test with both BHI and PPI (0.10 U/kg b.w.). To check the humoral response the variations of glucose, free fatty acids (FFA), prolactin, growth hormone, ACTH and plasma renin activity were evaluated. Blood glucose depression and further recovery by BHI and PPI administration paralleled each other, so were, prolactin, FFA, and plasma renin activity. A slight section of ACTH, and GH was observed under BHI challenge. There were not statistically significant differences between both insulins on any of the six parameters studied. The data do not confirm earlier published reports indicating hormonal and metabolic differences between human and porcine insulin.
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PMID:Metabolic and hormonal parameters after insulin-induced hypoglycemia in man, comparison between biosynthetic human insulin and purified pork insulin. 299 43

Angiotensin converting-enzyme inhibitors cross the placenta and modify the maternal, foetal and utero-placental renin-angiotensin system. Eight cases of pregnancy in women taking captopril have been published, 7 other cases being reported in this review paper. There were one spontaneous and 2 therapeutic abortions, one of which disclosed a malformation of uncertain diagnosis and imputation. One intrauterine death at 28 weeks was probably due to the severity of the maternal disease. Two children born to mothers also treated with frusemide died of neonatal anuria. Delivery or caesarean section occurred before term in 8 cases, and there were 3 cases of neonatal respiratory distress with a favourable outcome. Finally, one mother gave birth at term to twins of normal weight. The cases with respiratory distress can be attributed to the mother's hypertension, to prematurity and/or to concomitant treatment with beta-blockers, while the cases with anuria seem to be due to inhibition of the effects of angiotensin on renal haemodynamics, with salt depression as a possible aggravating factor. Treatment with angiotensin converting enzyme inhibitors does not seem to warrant therapeutic abortion. However, these drugs are contra-indicated in pregnancy and should only be given to women wishing to become pregnant if they present with resistant and dangerous arterial hypertension. A programme of pharmacovigilance is being set up to follow up such pregnancies.
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PMID:[Inhibition of angiotensin converting enzyme in human pregnancy. 15 cases]. 300 90

This study examined the effects of ageing on the cardiopulmonary receptor regulation of vasomotor tone in skeletal muscle and renin release by the kidney. To this end, the changes in forearm vascular resistance (mean arterial pressure divided by plethysmographically measured forearm blood flow), plasma noradrenaline concentration and plasma renin activity were measured in eight young (23 +/- 2 years, mean +/- s.e.m.) and seven elderly healthy subjects (69 +/- 2 years) during manoeuvres which altered cardiopulmonary receptor activity. The cardiopulmonary receptors were stimulated by increasing central venous pressure through passive leg-raising and deactivated by reducing central venous pressure through non-hypotensive (-15 mmHg) and hypotensive (-40 mmHg) levels of lower body negative pressure. During either manoeuvre, central venous pressure changed by the same amount in both groups, but the reflex changes in forearm vascular resistance, plasma noradrenaline and plasma renin activity were significantly less in elderly subjects. Since the increase in forearm vascular resistance induced by a cold pressor test was comparable in young and elderly subjects, a non-specific depression of cardiovascular responsiveness to neural stimuli can be excluded. Thus, healthy normotensive elderly subjects show an impairment of both vascular and neurohumoral influences exerted by cardiopulmonary receptors. This may be involved in the decreased ability of the elderly to cope with gravity challenges.
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PMID:Effects of ageing on the cardiopulmonary receptor reflex in normotensive humans. 307 75

With the failure of the heart as a pump, there ensues a series of neurohumoral compensations that defend organ perfusion at the expense of alterations in cardiac filling pressures and the distribution of blood flow to various regional circulations. Activation of the sympathetic nervous system and the renin-angiotensin II-aldosterone system and increases in circulating arginine vasopressin maintain arterial blood pressure by producing systemic arteriolar vasoconstriction and the renal retention of salt and water. Constriction of the efferent arterioles in the kidney by angiotensin II and norepinephrine promotes reabsorption of glomerular filtrate in the peritubular capillaries and maintains glomerular filtration in the face of declines in glomerular plasma flow and the glomerular permeability-surface area ultrafiltration coefficient. In resting, sodium-replete, conscious animals and humans, pharmacologic inhibition of renal cyclo-oxygenase by nonsteroidal anti-inflammatory drugs has little or no effect on renal hemodynamics. However, electrical or reflex stimulation of the renal nerves, intrarenal infusion of angiotensin II, or infusion of arginine vasopressin stimulates the release of vasodilator prostaglandins from the kidneys. In sodium-depleted animals or humans, and when cardiac output decreases, there is an increase in total peripheral vascular resistance but little change in renal vascular resistance. Increased renal synthesis of vasodilator prostaglandins (presumably by the blood vessels) maintains renal blood flow despite increased release of renin and norepinephrine from the kidneys. In these situations, pharmacologic inhibition of renal cyclo-oxygenase is accompanied by marked reductions in renal blood flow and glomerular filtration rate. When this occurs in patients with advanced heart failure, reversible oliguric renal failure may result. In this setting, cyclo-oxygenase inhibition may also increase arterial pressure and induce additional depression of cardiac function. Recent data indicate that blood vessels have the capacity to synthesize the sulfidopeptide leukotrienes C4, D4, and E4, which can constrict peripheral and renal blood vessels and alter vascular permeability. The vascular cell types responsible for leukotriene C4 synthesis and the potential roles of these vasoactive eicosanoids in kidney and other regional circulations are currently under study.
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PMID:Prostaglandins in congestive heart failure and the effects of nonsteroidal anti-inflammatory drugs. 309 62

The effects of intravenous acetylsalicylic acid (1.0 g bolus) on renal function and prostaglandin synthesis were evaluated in a prospective, controlled study in eight patients in an intensive care unit. Four of these patients had congestive heart failure. Administration of acetylsalicylic acid caused significant antidiuresis (-56%), antinatriuresis (-82%), renin suppression (-26%) and decreased GFR (-41%). All of these changes were completely reversible within 1-2 hours and tended to be more pronounced in the patients with congestive heart failure. Urinary excretion of prostaglandin E2 was depressed profoundly (-93%) and did not return to more than 45% of control 6 h after the administration of acetylsalicylic acid. We conclude that intravenous acetylsalicylic acid affects kidney function in a manner similar to other prostaglandin synthesis inhibitors. Its effects are, however, short-lived. The inhibition of urinary PGE2 excretion outlasts GFR depression, antidiuresis, antinatriuresis and renin suppression by several hours.
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PMID:Effects of intravenous aspirin on prostaglandin synthesis and kidney function in intensive care patients. 311 Jun 70


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