Plasma 6-keto-prostaglandin F1 alpha in disorders involving hypokalemia.

We measured plasma levels of 6-keto-prostaglandin F1 alpha by radioimmunoassay in patients with hypokalemia due to various disorders. Plasma 6-keto-PGF1 alpha in patients with disorders involving hypokalemia was not different from that of normal controls. Treatment with inhibitors of prostaglandin synthesis for 5-7 days in three patients with Bartter's syndrome decreased 6-keto-PGF1 alpha plasma levels by about 25%. It is suggested that, plasma 6-keto-PGF1 alpha may, on occasions, be a poor index of circulating prostacyclin.