THE PITUITARY GROWTH HORMONE 



373 



24- 



20- 



> 

 o 

 o 



0° 16 



E 

 o> 

 O 

 O 



Q 



UJ 



cr 



UJ 



> 



o 

 o 



UJ 

 (T 



vi 



t- 

 u 



>p 



12- 



8- 



4- 



40 80 120 160 



TIME -MINUTES 



200 



240 



Figure 9. The oxidation of palmitate-1-Ci^ to C^-^Oo by fed and fasted 

 hypophysectomized rats in response to acute growth-hormone treatment. 

 (Frankhn and Knobil, 1961). 



oxidation of labeled albumin-bound palmitate by rat diaphragm tissue 

 incubated in vitro ( Hotchkiss and Knobil, I960; Knobil, Franklin, and 

 Hotchkiss, 1960. ) In such a system, the fatty-acid content of the tissue 

 could at least be measured as an estimate of pool size. 



Diaphragms were excised from normal, hypophysectomized, and 

 hypophysectomized, growth-hormone-treated rats and were incubated 

 in a suitable medium containing labeled palmitate for two and four 

 hours. The CO2 was collected in base, precipitated as the carbonate, 

 and counted. The results, shown in Table V, permit the conclusion 

 that growth-hormone treatment did not increase the oxidation of 

 palmitate by the isolated muscle. Growth hormone added directly to 

 the medium yielded the same results. Hypophysectomy, if anything, in- 

 creased the fatty-acid utilization. Identical results were obtained in the 

 presence or absence of glucose in the medium, suggesting that a 

 preferential utilization of substrate was not a factor. That an actual in- 

 crease in palmitate oxidation may have been eflFected by growth- 

 hormone treatment but was masked by the diluting effect of endog- 



