THE PITUITARY BODY 



used to explain some of the cyclic sexual phenomena (e.g., 

 oestrus) which are observed in normal sexually mature 

 animals. 



The gonadotropic effects of the anterior pituitary after the 

 injection of oestrin and allied substances. ^'^ — Although Fluh- 

 mann and Kulchar (1931) were unable to demonstrate that 

 the administration of oestrin^" affected either the appearance 

 or the number of the "castration-cells" in the pars glandularis 

 of the spayed female rat, Hohlweg and Dohrn (1931-32) con- 

 cluded that appropriate doses of oestrone ("Progynon") pre- 

 vented both castration changes in the pituitary and an in- 

 crease in gonadotropic potency. To produce such effects they 

 estimated that the following doses of oestrone were required: 

 3^0" rat-unit per day to the spayed immature rat, and 5-6 rat- 

 units per day to the spayed adult rat.''^ Haterius and Nelson 

 (1932) prevented castration changes in the pituitary by suc- 

 cessfully transplanting ovarian tissue into adult castrated 

 rats.^' 



In normal rats — especially in females — the repeated injec- 

 tion of oestrone (and probably oestriol) causes a hypertrophy 

 of the pituitary. This effect is also observed in spayed rats. 

 The hypertrophy probably is due to the enlargement of the 

 pars glandularis (Leiby, 1931; Halpern and D'Amour, 1934; 



3' Oestrin, as the term is used here, usually refers to preparations causing oestrus 

 in ovariectomized mice or rats. Whenever it appears that a pure preparation — as 

 oestrone or oestriol — has been used, it has been so designated. 



'I" Total doses of 135-225 rat-units of oestrin were injected over periods of 77-90 

 days. 



"' The castrated immature rat required about j rat-unit per day. The dose of 

 oestrone for the adult spayed rat could be reduced to i rat-unit if i rabbit-unit of 

 progesterone (corpus luteum hormone) was also given. 



12 For other descriptions of the effects of oestrin on the pituitary of spayed or 

 castrated rats, see Montpellier and Chiapponi (19.30); Friedl (1933); Halpern and 

 D'Amour (1934); and Nelson (1934). It appears that oestrin is much less effective 

 in abolishing castration changes in the castrated male's pituitary. 



