Effect of Prostaglandin E₁on Plasma Free Fatty Acids and Blood Glucose in the Dog Prostaglandin and related factors 51

Intravenous infusion of prostaglandin E 1 (PGE 1 ) 0.2 μg/kg/min, during 30 min into 3 fasting, nonanesthetized dogs induced a rise of venous levels of FFA and glycerol followed by a decrease after the infusion. Infusion of PGE 1 high in aorta, 0.12–1.0 μg/kg/min, during 20–30 min into fasting, anesthetized dogs raised the arterial FFA levels in 9 of 12 dogs. In several of these experiments the FFA level started to decrease before the end of infusion. In the remaining 3 dogs the FFA level decreased during the infusion. Increase in plasma FFA was also seen in anesthetized dogs during administration of PGE 1 i.v. or in a common carotid artery. Studies on turnover rate of plasma FFA showed that the increased as well as the decreased concentration of FFA was entirely caused by changes in the rate of mobilization of FFA into blood plasma. The plasma levels of glycerol followed the same pattern as the FFA concentration. Neither in the nonanesthetized nor in the anesthetized dogs did PGE 1 produce any signiñcant effects on blood glucose. Administration of PGE 1 high in aorta into fasting, anesthetized dogs, 0.3–0.8 μg/kg/min, inhibited the enhanced FFA mobilization induced by noradrenaline, adrenaline or isoprenaline. The increase in FFA concentration induced by the sympathetic ganglionic stimulating agent DMPP was also inhibited by PGE 1 0.4/μg/kg/min, but the DMPP induced rise in blood glucose concentration was unaffected.