title: Insulin in vivo increases the in vitro fall of plasma potassium concentration in human venous blood.
abstract: Venous blood taken from fasting subjects at rest and incubated in vitro at room temperature for 120 min showed a mean fall in the plasma potassium concentration of 0.13 mmol l-1 (SEM 0.08, n = 6). Blood obtained 15 min after the intravenous administration of insulin (0.67 nmol kg-1 body weight) and incubated under the same conditions showed a significantly greater fall in the mean plasma potassium concentration of 0.33 mmol l-1 (SEM 0.09, P less than 0.05, n = 6). The addition of insulin (up to 33 nmol l-1) to blood taken from fasting subjects did not induce the phenomenon. The transfer of plasma from pre-insulin blood samples to blood cells obtained 15 min after insulin administration and vice versa indicated that the fall in plasma potassium concentration was a property of the 15 min post-insulin blood cells, presumably erythrocytes, rather than the plasma. The ouabain-suppressible component of 86Rb+ influx in erythrocytes obtained 15 min after the administration of insulin was virtually doubled compared to erythrocytes obtained before insulin suggesting increased activity of the sodium pump of erythrocytes.
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D008297:Male; D011188:Potassium / Q000097:blood*; D012964:Sodium / Q000097:blood
chemical_list: D001786:Blood Glucose; D007328:Insulin; D012964:Sodium; D011188:Potassium