THE PITUITARY BODY 



0.05-5.007 of oestrone daily into the gonadectomized part- 

 ners of the pairs 9 ? and 9 isT-"^ Rats 30-33 days old were 

 used and received injections for 11 days. The spayed female 

 appeared to be more sensitive than the castrated male (e.g., 

 weight of both ovaries of 9 of 9 9 without injection, 71.0 

 mg.; similar weight, 9 of 9 9 , if ? received oestrone, 24.0 

 mg.). This would be expected from the fact that ovarian 

 changes are usually more pronounced in the female of the 

 pair 9 sf • Also the authors concluded that by the technic 

 of parabiosis, a castration change in pituitary function is re- 

 vealed earlier than by studies of pituitary histology. 



According to Victor and Andersen ( 1 937) , oestrone or oestra- 

 diol causes a significant increase in the oxygen-consumption 

 of thepituitary of the rat, whether the hormone be added to 

 the surviving pituitary in vitro or administered to the spayed 

 rat about 6 hours before the gland is removed. No such 

 phenomenon was observed in control tissues (liver, kidney). 



^) Progesterone^'^ — Progesterone, like oestrone and andros- 

 terone, may cause regression of the testes in adult ring doves 

 (Bates, Riddle, and Lahr, 1937). To obtain this effect the 

 authors injected 0.25 Clauberg-unit each day for 10 days. 



According to Hohlweg (1935) the characteristic effects of 

 gonadectomy on the pituitary are not corrected by the in- 

 jection of progesterone, despite reports to the contrary. 

 Hohlweg found that the administration of 0,54 mg. of pro- 

 gesterone daily for two weeks to adult spayed rats did not 

 alter the histologic changes in the pars glandularis. He at- 

 tributed the positive results of other investigators to con- 

 tamination of their extracts with an oestrogen or an andro- 

 gen. Large doses of progesterone inhibit oestrus in the rat 

 (Selye, Browne, and Collip, 1936; Phillips, 1937). Associated 

 with this effect are moderate ovarian atrophy and some pitui- 



« For the meaning of the symbols, see pp. 78-79, n. 25. 



'•'' Zwarenstein (1937) concluded that progesterone causes ovulation in the toad 

 {Xenopus laevis) by its direct action on the ovary. Shapiro previously had found 

 that testosterone, androsterone, or certain derivatives of these, adrenal cortical 

 extract, etc., can cause ovulation in this amphibian. 



