Insulin in vivo increases the in vitro fall of plasma potassium concentration in human venous blood.
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.
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
D001786:Blood Glucose; D007328:Insulin; D012964:Sodium; D011188:Potassium