INFUSION OF VARIOUS SHORT-CHAIN FATTY-ACIDS CAUSES DIFFERENT CHANGES IN THE BLOOD-GLUCOSE AND INSULIN CONCENTRATIONS IN GROWING LAMBS DEPRIVED OF FOOD OVERNIGHT

Glucose and insulin concentrations of jugular blood plasma were monito red in growing lambs over 8 h, following a 2 h infusion of acetate, pr opionate, N-butyrate, n-valerate and physiological saline Into the rum inal vein. Propionate and especially n-valerate infusion significantly increased blood glucose concentration. n-Butyrate induced only a smal l increase of shorter duration, while acetate failed to exert a pronou nced effect on the blood glucose level. SCFA infusion, except for acet ate, raised the insulin level in the blood. Relative rise was closely correlated with the length of carbon chain of the SCFA, that is, n-val erate caused the largest elevation of the insulin level, followed by n -butyrate and propionate. At the same time, acetate failed to cause a marked influence on the insulin level. These results of insulin showed agreement with glucose concentration changes, with the exception of n -butyrate rate treatment, where the increase of plasma insulin concent rations after the infusion proved to be much larger than that of gluco se, relative to the preinfusion value.