THE PITUITARY GROWTH HORMONE 



371 



80 120 160 



TIME -MINUTES 



200 



240 



Figure 7. The effect of fasting and glucose feeding on the conversion of 

 palmitate-l-C^^ injected intravenously, at O time, to C'^Oo by normal rats. 

 The counts recovered in the expired COo are cumulative. The vertical lines 

 represent standard errors of the means. (Franklin and Knobil, 1961) . 



could be detected by this system. Removal of the pituitary gland did 

 not influence the pattern of palmitate-C^^ oxidation to C^^02, whether 

 the hypophysectomized animals were fasted or fed ( compare Figure 7 

 with Figures 8 and 9). Treatment of hypophysectomized animals with 

 growth hormone ( three mg. per rat ) for four days prior to the experi- 

 ment similarly did not affect the conversion of administered palmitate 

 to CO2 (Figure 8). The total CO2 output and the specific activity of 

 the expired CO2 of the animals treated with growth hormone did 

 not differ significantly from that observed in the hypophysectomized 

 controls. 



The administration of a single dose of growth hormone ( three mg. 

 per rat) five hours before the injection of labeled palmitate signifi- 

 cantly decreased the recovery of labeled carbon dioxide in the fasted 

 hypophysectomized animals, but it was without effect in the glucose- 

 fed rats ( Figure 9 ) . This effect of growth hormone in the fasted group 

 was reflected in a significant reduction in the specific activity of the 

 respired CO2, and it could best be accounted for by a dilution of the 

 labeled palmitate by endogenous fatty acids mobilized in response to 



