156 



PHYSIOLOGICAL TRIGGERS 



rate about 20 hours after the intravenous administration of estradiol. In con- 

 trast to the metaboUc events occurring at 4 hours, stimulation of glucose dis- 

 appearance 20 hours after estrogen was accompanied by a marked depression 

 in lactate accumulation. Only about one-fourth of the glucose disappearing 

 at the 20-hour peak appeared as lactate. Presumably, a large portion of the 

 remainder was completely oxidized and served as the source of the added energy 

 represented by the large increase in oxygen utilization at this time. Under 

 anaerobic conditions the glycolytic rate was somewhat higher than that ob- 

 served under aerobic conditions, and most of the glucose disappearing could 

 be accounted for on the basis of formed lactate. 



-IS 

 g|40 



oi 



< 



h|20 



1' 



< 



10 



HOURS AFTER ESTROGEN 

 1 I 1 1 J- 



cn 

 19 zq: 



O X 



o 



Fig. 3. 

 estrogen 

 glycolysis 



Influence of lime after 

 injection on aerobic 

 by the uterus of the 

 castrated rat. Each point repre- 

 sents the mean ± standard error 

 of values obtained in 6-41 experi- 

 ments. Open circles, glucose dis- 

 ap|)earance; solid circles, lactate 

 accumulation; crosses, oxygen con- 

 sumi)tion. All figures are the total 

 values for the 3-hour incubation 

 period. Dosage of estradiol, 0.5 

 )ug/ioo gm body weight. (Re- 

 printed from ref. 25 by permission 

 of the editors.) 



10 



15 



20 25 



Quite analogous data have been obtained by Levey and Szego (18) in study- 

 ing the glycolytic and oxidative metabolism of the seminal vesicle of the cas- 

 trated guinea pig with and without androgen treatment. 



It will be recalled that the respiration of the uterus of the castrated rat, 

 incubated in a glucose medium, was essentially unchanged 4 hours after the 

 intravenous administration of estradiol alone (cf. tig. 2). This is shown again 

 in figure 4, from which it is also evident that Cortisol or deso.xycorticosterone, 

 injected simultaneously with estradiol 4 hours earlier, were likewise without 

 effect on the respiration of the uterus. On the other hand, the marked stimu- 

 lation of uterine respiration 20 hours after estrogen injection (solid circles) was 

 almost completely prevented by the simultaneous administration of Cortisol 

 (squares). Desoxycorticosterone {Iriaugles), given together with estradiol, 

 exhibited no antagonistic effect. Moreover, the increase in aerobic- glycolysis. 



