Hypotension-induced hypokalaemia in sheep.
Plasma K+ was measured in Merino ewes during 50-90 min periods of hypotension induced by sodium nitroprusside, isoprenaline, verapamil or nifedipine. Doses were adjusted to produce falls in systemic blood pressure of approximately 20 mmHg. All of these drugs caused decreases in plasma K+ which could not be attributed to increased urinary excretion of K+. In all cases plasma renin activity increased during the hypotension. Plasma aldosterone concentration which was measured in some sodium nitroprusside experiments also increased during the hypotension. However, enhancement of the plasma renin activity and plasma aldosterone concentration responses by prior sodium depletion of the sheep by furosemide administration or suppression of the plasma renin activity and plasma aldosterone concentration responses by prior salt loading did not influence the magnitude of the hypotension-induced hypokalaemia.
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D007008:Hypokalemia / Q000097:blood / Q000209:etiology*; D007022:Hypotension / Q000097:blood / Q000139:chemically induced / Q000150:complications* / Q000503:physiopathology; D011188:Potassium / Q000097:blood; D012079:Renal Circulation / Q000187:drug effects; D012083:Renin / Q000097:blood; D012756:Sheep; D012965:Sodium Chloride / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D012965:Sodium Chloride; D012083:Renin; D011188:Potassium