Suppression of splanchnic ketone body production in man by nicotinic acid.

The effect of nicotinic acid on splanchnic blood flow and splanchnic metabolism of free fatty acids andβ-hydroxybutyric acid was studied in four normal subjects, two patients with diabetes and one patient with uncomplicated obesity. The main purpose of the study was to explore the mechanism behind the reduction in plasma levels ofβ-hydroxybutyric acid induced by nicotinic acid. — Plasma levels of free fatty acids andβ-hydroxybutyric acid were promptly reduced by nicotinic acid. There was a positive correlation between the arterial concentration of free fatty acids and the arterial — hepatic vein difference of free fatty acids. From this apparently linear relationship it was calculated that at any arterial level of free fatty acids one quarter of the amount of free fatty acids delivered to the splanchnic region was taken up there. — The splanchnic production ofβ-hydroxybutyric acid was, on the average, reduced by 95 per cent 40 and 60 minutes after administration of nicotinic acid. It is suggested that reduced hepatic formation ofβ-hydroxybutyric acid is the main cause of the lowering of plasma levels of this ketone body after administration of nicotinic acid to man.