1196 



HORMONAL REGULATION 



old had dropped, as it does in females simi- 

 larly treated, but it is not stated that estrus 

 was induced. 



Relationship 6. The display of feminine 

 behavior by females treated with androgens 

 has been reported. The action of small 

 amounts of androgen in the production of 

 breeding behavior in the black-crowned 

 night heron (Noble and Wurm, 1940a) is 

 believed to be normal. Three intact and 3 

 spayed lizards containing pellets of tes- 

 tosterone propionate displayed estrous be- 

 havior and accepted other treated females 

 or males in copulation (Noble and Green- 

 berg, 1941b). In an experiment involving 

 injections of testosterone propionate into 

 a female mammal, 4 of 10 spayed rats ex- 

 hibited lordosis, 7 showed the hopping re- 

 sponse, and 1 displayed quivering of the 

 ears (Beach, 1942b). It was said of the re- 

 actions that they did not appear frequently. 

 Treatment with testosterone propionate in 

 various combinations and amounts after 

 PMS was followed by the appearance of 

 estrous responses in anestrous ewes (Cole, 

 Hart and Miller, 1945), but ovulation also 

 occurred in some animals; consequently, the 

 the hormone responsible for estrus cannot 

 be stated with certainty. 



Striking effects are described by Klein 

 (1952) in his review of experiments per- 

 formed by Gaston Mayer and himself. Fol- 

 lowing the implantation of pellets of tes- 

 tosterone propionate or acetate into the ears 

 of intact female rabbits, estrous behavior 

 was displayed that was comparable with and 

 even stronger than that w^iich followed 

 treatment with estrogens. As in the work on 

 the ewe, identification of the hormonal 

 stimulus is made difficult by the occurrence 

 of ovulation with ''generations and genera- 

 tions" of corpora lutea. Intact female cats, 

 on the other hand, were brought into heat 

 with testosterone propionate, and ovulation 

 did not occur. Largely because of the strik- 

 ing display of feminine behavior by rabbits 

 containing pellets of androgen (Klein, 

 1952), Kawakami and Sawyer (1959a) 

 studied the effects of androgen on the be- 

 havior of estrogen-primed ovariectomized 

 female rabbits and on the associated EEG 

 arousal thresholds. With a high dose es- 

 pecially, estrus was maintained, but it 



should be noted that in this experiment the 

 testosterone appears to have substituted for 

 progesterone in maintaining estrus rather 

 than to have acted by inducing estrus. 



The strongest opinion that androgen 

 stimulates feminine behavior in females is 

 perhaps that held by clinicians. Their many 

 reports that androgens increase sexual de- 

 sire in the human female (Shorr, Papani- 

 colaou and Stimmel, 1938; Loeser, 1940; 

 Salmon, 1942; Salmon and Geist, 1943; 

 Greenblatt, 1943; Abel, 1945; Carter, 

 Cohen and Shorr, 1947; Foss, 1951 ; Waxen- 

 burg, Drellich and Sutherland, 1959), ap- 

 parently more effectively than endogenous 

 estrogens, certainly strengthens the likeli- 

 hood suggested by much of the work with 

 lower mammals that androgen substitutes 

 for estrogen. However, before the possibility 

 of such an action is given complete accept- 

 ance, we should be able to exclude the re- 

 mote possibility that the effective substance 

 is the androgen rather than a metabolite 

 with estrogenic action (Dorfman and Un- 

 gar, 1953; Dorfman and Shipley, 1956; 

 West, Damast, Sarro and Pearson, 1956; 

 Davis and Plotz, 1957). 



Relationship 8. The frequency with which 

 masculine behavior is displayed by intact fe- 

 males suggests that the neural mechanisms 

 mediating tiiis behavior are well developed. 

 If so, it could follow that the display of 

 masculine behavior by the female in re- 

 sponse to androgenic stimulation is more 

 easily achieved than the display of feminine 

 behavior by males in response to estrogenic 

 stimulation (relationship 4). From what fol- 

 lows and from the numerous cases cited by 

 Dorfman and Shipley, (1956, pp. 194-197), 

 this seems to be true, but it will be clear, 

 that even here, there is much evidence for 

 the refractoriness encountered in the other 

 relationships involving the action of hetero- 

 sexual hormones. 



No details are given, but pregneninolone 

 and testosterone induced male mating be- 

 havior in immature and mature female 

 guppies after 20 days of treatment (Ever- 

 sole, 1941), and methyl-dihydrotestosterone 

 injected into intact female mekadas was 

 effective as early as the 3rd day (Okada 

 and Yamashita, 1944). Elements of male 

 sexual behavior appeared in a definite se- 



