1184 



HORMONAL REGULATION 



followed the discovery that the adrenal 

 cortex is a source of androgenic substances. 

 The suggestion was made that such andro- 

 gen compensates for the loss of testicular 

 androgen following castration (Sollenberger 

 and Hamilton, 1939; Spiegel, 1939; Hamil- 

 ton, 1943a). Supporting evidence, however, 

 has not been advanced. On the contrary, 

 castrate men are found in which urinary 

 titers are very low (Hamilton, 1943b). The 

 level of sexual activity attained by pre- 

 puberally castrated male hamsters was not 

 lower in animals that w^ere castrated and 

 adrenalectomized (Warren and Aronson, 

 1957). In two experimental studies the post- 

 castrational sexual behavior of the adult 

 male dog and hamster was not altered fur- 

 ther by adrenalectomy (Schwartz and 

 Beach, 1954; Warren and Aronson, 1956). 

 Neither desoxycorticosterone acetate nor 

 cortisone substituted for testosterone in the 

 restoration of mating behavior in the cas- 

 trated male cat (Green, Clemente and de 

 Groot, 1957). Also in the male cat, the per- 

 sistence of sexual behavior after castration 

 could not be attributed to any androgens 

 secreted by the adrenal cortex ( Gooper and 

 Aronson, 1958). 



As in other fields of endocrinologic study, 

 investigators interested in the hormonal con- 

 trol of mating behavior turned from ex- 

 periments involving ablation of the organs 

 thought to be involved to replacement ther- 

 apy. Gonad transplantation, the administra- 

 tion of crude extracts, and treatment with 

 chemically purified and synthetic hormones 

 were attempted. The results following gonad 

 transplantation and the use of crude ex- 

 tracts are largely of historical interest and 

 are summarized in the older reviews. The 

 discussion which follows is limited to the 

 results obtained after administration of 

 the synthetic androgens, for the most part, 

 testosterone propionate. 



In general, claims of the effectiveness of 

 testosterone propionate have been advanced 

 with fewer reservations than those with re- 

 spect to the effects of castration. Infrequent 

 injections into male salmon parr were only 

 partly effective in restoring the pattern of 

 behavior in castrates (Jones and King, 

 1954). On the other hand, the full pattern 



of Ijehavior was induced in young male 

 guppies by treatment with pregneninolone 

 or testosterone (Eversole, 1941). Daily in- 

 jections of testosterone propionate or ace- 

 tate were effective in castrated cockerels 

 (Roussel, 1936; Davis and Domm, 1943), 

 rats (Shapiro, 1937b; Moore and Price, 

 1938; Stone, 1939a; Beach, 1944b; Beach 

 and Holzi-Tucker, 1949), rabbits (De Fre- 

 mery and Tausk, 1937), and guinea pigs 

 (Moore and Price, 1938; Grunt and Young, 

 1952b). AVhen castration was performed 

 several weeks or months before the be- 

 ginning of replacement therapy, 4.5 to 8.9 

 mg. restored copulatory ability in the rat, 

 and 150 mg. did so in the rabbit. When rats 

 were castrated and injected daily beginning 

 48 hours later, 50 to 75 /^g. of testosterone 

 l)roiiionate were sufficient for the main- 

 tenance of most of the measures of sexual 

 behavior at the precastrational level. After 

 the attainment of this level by injected, 

 castrated guinea pigs at the end of the 8 

 weeks, 25 /xg. per 100 gm. body weight per 

 day was more than a maintenance dose. 



Results obtained by Grunt and Young 

 (1952b, 1953) suggested new concepts of 

 the role of testicular hormone in the mainte- 

 nance of male sexual behavior. As we have 

 noted (p. 1179), every colony of animals 

 contains males showing different degrees of 

 sexual performance. The point was made 

 the ol)ject of an experiment in which males 

 were divided into high, medium, and low 

 score groups on the basis of their perform- 

 ance in 10 preliminary tests. They were 

 then castrated and, after the regressive 

 changes had reached a base-line, injected 

 daily with 25 fjug. hormone per 100 gm. 

 body weight. It was found that individuals 

 characteristically high, medium, or low 

 score before gonadectomy returned to the 

 corresponding level during the period of re- 

 placement therapy. Hormone injections of 

 50, 75, and 100 ;u.g. per 100 gm. body weight 

 daily were no more stimulating to sexual 

 behavior than the smaller quantity. Subse- 

 quently, 8 low" score males were injected 

 daily for 30 days with 500 /xg. testosterone 

 propionate per 100 gm. body weight, but 

 not even this large amount raised the level 

 of the animals' performance above that dur- 



