GONADS AND THE PITUITARY BODY 



sensitive tests — ovarian changes in the immature mouse, and 

 ovulation in the rabbit). Even in the hypophysectomized 

 rat, Smith (1927, 1930) could produce no favorable effect on 

 the ovary by injecting crude extracts of the anterior lobe of 

 the ox, although growth was promoted by the treatment; in 

 fact, crude or even refined extracts antagonized the gonado- 

 tropic effects of implants, pregnant mare's serum, and prolan 

 (Smith; Evans and others, 1933; Leonard, 1934). In the 

 female rat, receiving repeated injections either from an early 

 age or after sexual maturity, extracts of the ox gland caused 

 the extensive formation of corpora lutea atretica; the oes- 

 trous cycles either did not appear or appeared infrequently; 

 the rats became sterile (Long and Evans, 1921-22, Evans, 

 1924; Brouha and Simmonet, 1928; Lepine, 1931; D'Amour 

 and van Dyke, 1933; and McPhail, 1933). In the male mouse 

 or rat, implants or extracts of the anterior lobe of the ox ap- 

 pear to affect the testes adversely. After the repeated injec- 

 tion of extracts, fertility may be preserved but the size of the 

 testes (and tubules) may be reduced. Implants or extracts of 

 the anterior lobe of the ox may inhibit the growth of the 

 testes, spermatogenesis, and the activity of the interstitial 

 cells (some interference with the growth of the secondary 

 sexual organs).'-' 



The effects of implants or extracts of the pars glandularis 

 of the ox on the gonads of other animals are discussed in the 

 sections which follow. 



The pars glandularis of the sheep is of interest because it 

 constitutes one of the best sources of gonad-stimulating ex- 

 tracts. Judged by different assay techniques, sheep glands 

 are rich in the gonadotropic hormone(s). The anterior lobe of 

 the pig — although less satisfactory than that of the sheep — 

 appears to be a good source for obtaining the hormone. 



'^ Crafts and Flower (1925); Evans and Simpson (1926); Brouha and Simmonet 

 (1929); Lepine (1931); and Robson (1933). Brouha and Simmonet reported that 

 small but not large doses of an extract of the ox gland might hasten the development 

 (but not the growth) of the testes of the young mouse. 



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