Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of i.v. ergonovine tartrate infusions (0.05-20 micrograms/kg/min, 12 minutes duration) on coronary arteries was studied in 14 conscious dogs instrumented to continuously measure vascular diameter by an ultrasonic dimension gauge using 10-MHz piezoelectric crystals. Ergonovine induced a biphasic coronary response: small, transient dilation during the first minutes of infusion, followed by slowly developing constriction reaching its maximum 5 to 15 minutes after the end of the infusion and persisting at this level for at least 10 minutes. The threshold dosage for significant constriction was 0.05 microgram/kg/min. A dosage of 5 micrograms/kg/min (cumulative 60 micrograms/kg, corresponding to 35 micrograms/kg ergonovine maleate) caused a decline in mean left circumflex artery diameter by 137 +/- 15 micrometers (= 4.6%) without significantly altering heart rate, plasma catecholamines or plasma renin activity. Coronary venous O2 saturation did not decline, indicating the absence of coronary resistance vessel constriction. The epicardial artery constriction was not attenuated by a vasopressin antagonist. Under adrenergic blockade (2 mg/kg phentolamine and 2 mg/kg nadolol) or under ganglionic blockade (5 mg/kg pentolinium tartrate), ergonovine (5 micrograms/kg /min) caused substantial elevation in mean arterial pressure, while the decline in coronary artery diameter was attenuated. When this increase in arterial pressure was prevented by appropriate bleeding, the ergonovine-induced coronary constriction was not diminished by adrenergic or ganglionic blockade. The serotonin antagonist methysergide (0.5 mg/kg) completely abolished the ergonovine-induced coronary artery vasomotion. It is concluded that ergonovine in dogs causes an epicardial coronary artery constriction comparable to the diffuse coronary artery narrowing in men not suffering from variant angina pectoris. These constrictions are not mediated by an adrenergic mechanism.
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PMID:Ergonovine-induced constrictions of epicardial coronary arteries in conscious dogs: alpha-adrenoceptors are not involved. 612 80

Ergometrine usually depresses the S-T segment as in coronary insufficiency, when injected intravenously in rabbits with experimental coronary atherosclerosis and in patients with effort angina, but not in normal animals and man. To explain this difference, we carried out Langendorff perfusion studies in 32 normal and 29 atherosclerotic isolated rabbit hearts. Preliminary tests with ergometrine were done to ensure that advanced coronary atherosclerosis had developed in the rabbits fed a cholesterol diet; pathological examination of the heart after perfusion confirmed the result of the final test with ergometrine. Before drugs were perfused, the basal rate of coronary flow was greater, the heart rate was slower and the contractile amplitude was smaller in the atherosclerotic than in the normal hearts; nitroglycerin markedly increased flow in both normal and atherosclerotic groups. Ergometrine consistently caused a reduction in contractile amplitude with negligible changes in heart rate in both normal and atherosclerotic hearts. On coronary flow, however, the effects of ergometrine differed significantly in these groups; in doses of between 0.2 and 0.4 mg., the average decrease in flow was 8% in normal and 22% in atherosclerotic hearts. The effect was more variable in normal hearts and an increase in flow sometimes occurred. The difference in the response of normal and atherosclerotic hearts was particularly striking when ergometrine was given during recovery from a reduction of coronary flow which had been induced by vasopressin. Ergometrine then uniformly increased flow in the normal, but usually had the opposite effect in the atherosclerotic heart. In normal and atherosclerotic hearts, cardiac effects of vasopressin were similar. Tachyphylaxis to vasopressin, but not to ergometrine, was observed.
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PMID:Effects of ergometrine (ergonovine) on the isolated atherosclerotic heart of the cholsterol-fed rabbit. 1440 56