THE EFFECTS OF HYPOPHYSECTOMY 



tions of the uterus due to the injection of oestrone (theehn) 

 are inhibited by actively secreting corpora lutea (pregnancy 

 or pseudopregnancy); this inhibition, however, was not ob- 

 served 48 hours after the hypophysectomy of rabbits on the 

 fifth or sixth day of pregnancy or pseudopregnancy. Mori- 

 moto and Ikeda (1932) stated that the uterus of the hypo- 

 physectomized rabbit could be electrically stimulated (tech- 

 nique not described) less readily than that of the normal 

 rabbit. Saito (1934) studied some aspects of the carbohy- 

 drate metabolism in hypophysectomized and normal rabbits. 

 Hypoglycemia could be observed particularly in operated 

 animals which were cachectic. In comparison with normal 

 rabbits, hypophysectomized rabbits exhibited a greater sus- 

 ceptibility to insulin and a smaller increase in the concentra- 

 tion of the blood sugar after the injection of epinephrin. 



White (1932) and Firor (1933) have investigated the effect 

 of the removal of the pituitary body from pregnant rabbits. 

 Ovulation but not implantation occurred if hypophysect- 

 omy was done 50 minutes (White: 60 to 75 minutes) to 

 3 days after copulation. Hypophysectomy on the fourteenth 

 day post coitum caused, as a rule, fetal resorption; the 

 later performance of the operation (17-28 days) usually 

 caused a termination of the pregnancy within 48 to 72 

 hours." The expelled fetuses were either dead or lived only 

 a few hours. Apparently parturition can occur in the ab- 

 sence of all parts of the pituitary body (Firor). 



McPhail and Parkes (1933) have described the technique 

 of hypophysectomy in the hedgehog. 



Observations on the technique and effects of hypophysec- 

 tomy in ferrets have been made by Hill and Parkes (1932-33) 

 and by McPhail (1933, 1935)- In the ferret, as in the rabbit 

 and cat, ovulation ordinarily occurs only after copulation. 

 Hypophysectomy prevents ovulation in the ferret provided 

 that it is performed within i hour after the beginning of 



" Firor's control rabbits delivered 30-34 days after copulation. 



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