[On the influence of catecholamines on the turnover rate of free fatty acids and the formation of plasma triglycerides]

Effect of noradrenaline on triglyceride and glycogen concentrations in liver and muscle from man

Fifteen male subjects aged 21-29 were given noradrenaline infusions for 4 hr. The noradrenaline infusions started at a rate of 0.1 mug/kg/min and were increased stepwise at hourly intervals. Blood was sampled before and at hourly intervals during and after the noradrenaline infusions. Needle biopsies were taken from the femoral muscle in 10 subjects and frim the liver in 8 subjects before and after the noradrenaline infusion. The concentrations of FFA in lasma and of beta-hydroxybutyric acid in blood were markedly elevated during noradrenaline infusion. The concentrations of plasma TG and blood glucose were slightly elevated. In liver the TG concentration increased from 23.1 to 32.7 mmole/kh (p smaller than 0.001). It was estimated that the de novo synthesis of TG in the liver could have required about 30% of the plasma FFA entering the slanchnic region. In muscle the TG concentration was 3.6 mmole/kh lower after the noradrenaline infusion (p smaller than 0.001). No change was found in the concentrations of cholesterol and phospholipids in muscle or of cholesterol in liver. The glycogen concentration in muscle did not change during noradrenaline infusion. The decrease in liver glycogen concentration was of the same order of magnitude as previously observed in fasting man. The results suggest that noradrenaline was without major net effects on the metabolism of glycogen in liver and muscle.