GONADS AND THE PITUITARY BODY 



Kraul (1931) treated various animals with corpus luteum 

 extract, oestrin, etc., and then implanted the pituitary of the 

 treated rabbits, guinea pigs, etc., into immature female mice. 

 He concluded that the effect of the implant was related to the 

 type of extract previously injected into the animal serving as 

 donor. For example, if the donor-animal had received injec- 

 tions of corpus luteum extract, the predominant effect of its 

 pituitary on the ovary of the immature mouse was luteiniza- 

 tion. So far as the author is aware, there is some evidence 

 against this view, but none other in favor of it. 



In mice, as in rats, atretic corpora lutea may follow the use 

 of implants, but they appear to be more frequently observed 

 after the injection of extracts. The reverse is true of ovu- 

 lation. 



The effect of injections of a gonadotropic extract (sheep 

 pituitary) for periods longer than that usually employed (4-5 

 days) has been investigated by Fluhmann (1933). The effect 

 of a given dose of the extract on the weight of the ovary of the 

 immature rat was greatest if the whole amount was given 

 within 5 days. If the administration of the total dose was 

 completed only after 10-20 days, the ovarian hypertrophy 

 was less. Even if the daily dose was continued for 20 days (so 

 that the total dose was much increased) the effect was not 

 greater than after 5 days except when large doses were em- 

 ployed. Vogt (1931) found that the extirpation of the su- 

 perior cervical ganglion and the interganglionic nerves pre- 

 vented, in eight of thirteen adult female rats, pseudopreg- 

 nancy due to the irritation of the cervix by means of a glass 

 rod. The operation did not prevent pregnancy or pseudo- 

 pregnancy due to mating between operated female rats and 

 normal or vasectomized bucks. Her data, therefore, hardly 

 support the conclusion that the liberation of gonadotropic hor- 

 mone from the pituitary (pseudopregnancy following the irri- 

 tation of the cervix by a glass rod) may be initiated by nerv- 

 ous stimuli passing by way of the cervical sympathetic. 



[131] 



