THE PITUITARY BODY 



This statement is based on the investigation of only a few 

 preparations (Hill and others, 1934; Nelson and Overholser, 

 1935). Neither mouse- nor rat-units can be stated in terms of 

 rabbit-units. 



How many gonadotropic hormones are there? — Together 

 with the papers of the authors listed below/^ many other re- 

 ports have been used as a basis for postulating the secretion 

 of different gonadotropic hormones by the pars glandularis.^^ 



As many as five different hormones have been suggested: 



1. An oestrogenic hormone which, by acting on the ovary, causes a Hbera- 

 tion of "oestrin" accompanied by anatomical changes in the uterus 

 and vagina but not in the ovary. 



2. A hormone causing follicular growth. This hormone may even be 

 divided into two hypothetical substances with respect to the effects on 

 the granulosa and may or may not be regarded as identical with 



3. A hormone causing follicular maturation. This hypothetical hormone 

 may or may not be considered the same as another hypothetical hor- 

 mone, that causing sensitization of the follicle and permitting luteiniza- 

 tion by the luteinizing hormone. Hormones 2 and/or 3 may be de- 

 scribed as that (or those) responsible for potentiating the gonado- 

 tropic effects of prolan in immature rats. 



4. A hormone producing ovulation. 



5. A hormone producing luteinization — even occasionally subdivided 

 with respect to lutein-cell transformation of the granulosa or the theca 

 interna. 



How these various "hormones" are related to the gonadotropic 

 hormone(s) responsible for the growth and maintenance of the testis 

 is not known. Some observations suggest that the follicle-stimulating 

 hormone stimulates the testis; other observations speak equally in 

 favor of the luteinizing hormone. There is evidence that spermato- 

 genesis chiefly depends upon a follicle-stimulating principle [Smith 

 and Engle, 1934]. 



^* Loeb (1930); Aron, Fevold and others. Hill and Parkes, Lepine (1931); Lip- 

 schutz and others, Schockaert (1932); Aschheim, Collip and others, Evans and 

 others, Fevold and others, Lipschiitz, Loeb and Friedman, van Dyke and Wallen- 

 Lawrence (1933); Bates and others, Dingemanse, Fevold and others. Hertz and 

 Hisaw, Hisaw and others, Hohlweg, Lane and Hisaw, Lipschiitz, VVallen-Lawrence, 

 Witschi and Levine (1934); Lipschiitz, Pfeiffer, Selye and others (1935). The fol- 

 lowing authors discuss the potentiation of the gonadotropic effects of prolan by the 

 administration of anterior-pituitary extract: Evans and others (1932-34); Leonard 

 (1932); Collip and others, Fevold and others (1933); Engle, Leonard (1934). 



''» Prolan (etc.) is discussed in chap. v. 



[ 174 ] 



