Blood pressure and metabolic effects of 18-OXO-cortisol in sheep

18-Oxo-cortisol (18-oxo-F) has been isolated from the urine of subjects with primary aldosteronism. This study examines the pressor, mineralocorticoid and glucocorticoid effects of 18-oxo-F in conscious sheep—a well studied species for the assessment of the pressor effect of steroid hormones. 18-oxo-F (24 mg/day i.v. for 5 days, n= 3) increased mean arterial pressure MAP (64 ± 2 mmHg control and 75 ± 6 mmHg on day 5 P < 0.001). There was no change in heart rate. Plasma [K +] decreased from a control of 4.3 ± 0.1 mmol/1 control to 2.9 ± 0.3 rnmol/l on day 5 ( P < 0.001). Urinary Na + excretion decreased on the first infusion day (233 ± 18 mmol/day control and 124 ± 20 mmol/day on infusion day l P < 0.001). Urinary K + excretion was reduced on days 1, 4 and 5 of the infusion. Thus in sheep, 18-oxo-F increased blood pressure associated with in vivo evidence of mineralocorticoid activity.