WHOLE-BODY AND SPLANCHNIC METABOLIC AND CIRCULATORY EFFECTS OF GLUCOSE DURING BETA-ADRENERGIC-RECEPTOR INHIBITION

The aim of the study was to assess the possible contribution of adrene rgic mechanisms to the thermogenic and circulatory effects of glucose ingestion. With the use of indirect calorimetry and arterial, pulmonar y arterial, and hepatic venous catheterization, whole body and splanch nic oxygen uptake and blood flow were examined in nine propranolol-tre ated healthy male volunteers before and during 2 h after oral ingestio n of 75 g of glucose. The glucose effects were compared with those in nine untreated controls. After propranolol, the glucose-induced rise i n splanchnic blood flow was reduced by similar to 60%, and the hepatic venous glucose release to the systemic circulation was significantly delayed. Glucose-induced increments in pulmonary and splanchnic oxygen uptake and cardiac output were similar in the two groups. It is concl uded that adrenergic mechanisms contribute to the glucose-induced rise in splanchnic blood flow and thereby probably to the time course for intestinal absorption of nutrients. It is suggested that the magnitude of glucose-induced thermogenesis is independent of adrenergic stimula tion.