398 



PHYSIOLOGY OF GONADS 



Freund and Thompson (1957) reported 

 that intravenous injection of crude guinea 

 pig coagulating gland secretion into rab- 

 bits or guinea pigs induces hypotensive 

 shock. Edema results if the secretion is 

 injected locally. The secretion of the co- 

 agulating gland of the rat does not possess 

 these properties. Further studies by Freund, 

 Miles, Mill and Wilhelm (1958) showed 

 that two main protein fractions can be sep- 

 arated from the secretion of the guinea pig 

 coagulating gland by preparative starch 

 electrophoresis. Fraction I was hypotensive 

 and a potent permeability factor in rabbits 

 and guinea pigs. It hydrolyzed TAMe rap- 

 idly and may be identical with the TAMe- 

 hydrolyzing enzyme described in guinea 

 pig coagulating gland l)y Gotterer, Banks 

 and Williams-Ashman (1956). The latter 

 enzyme is not present in the coagulating 

 gland of the rat. Fraction II isolated by 

 Freund and his associates is ]n"obably vesic- 

 ulase. 



III. Structure and Function in 

 Relation to Hormones 



A. INTRODUCTION 



Some of the effects of removal of the 

 testes in males have been recognized ever 

 since castration was first practiced on man 

 and domestic animals. Aristotle's writings 

 include accurate descriptions of the effects 

 of castration on secondary sex characters 

 in birds and in man. The classical studies 

 of John Hunter (1792) laid the basis for 

 an understanding of the relation between 

 the presence of the testes and the size and 

 functional state of the accessory reproduc- 

 tive glands of mammals, although he did 

 not postulate the existence of testicular 

 hormones. 



Hunter demonstrated experimentally 

 that the seminal vesicles of guinea pigs are 

 not reservoirs for semen and concluded that 

 this a])plies to the seminal vesicles in man 

 and in other mammals. He not only de- 

 scribed the gross anatomy of the seminal 

 vesicles in many species (hedgehog, iiiole. 

 man, boar, bull, horse, buck, mouse, rat, 

 beaver, guinea pig) and their absence fi'om 

 others, but he observed tliat they arc smaller 

 in the gelding than in the stallion. In 

 refei'ence to other glands, he generalized 



that "the prostate gland, Cowper's glands 

 and the glands along the urethra . . . are in 

 the perfect male large and pulpy, secreting 

 a considerable quantity of slimy mucus 

 which is salt to the taste . . . while in the 

 castrated animal these are small, flabby, 

 tough and ligamentous, and have little se- 

 cretion." In addition, he made the equally 

 important discovery that the testes of 

 mammals (and birds as well) are very 

 small in winter in animals ''which have 

 their seasons of copulation" and the semi- 

 nal vesicles and prostates are "hardly dis- 

 cernable." He concluded that "from these 

 observations it is reasonable to infer that 

 the use of the vesiculae in the animal 

 oeconomy must, in common with many 

 other parts, be dependent upon the testi- 

 cles." 



Over 100 years later, many of his obser- 

 vations were rediscovered, extended, and 

 interpreted in the light of the first demon- 

 stration that the testis is an endocrine or- 

 gan (Berthold, 1849). In the early part of 

 the 20th century the interest in attempting 

 to isolate and characterize androgens from 

 testis tissue and urine led to a search for 

 rapid and dependable bioassay methods. 

 The cock's comb provided a sensitive and 

 convenient test object (Pezard, 1911). In 

 addition, some of the accessory reproduc- 

 tive glands of mammals were found to 

 atrophy rapidly after castration and proved 

 also to be sensitive indicators for the pres- 

 ence of androgenic hormones. Cytologic 

 tests using the rat prostate, seminal vesi- 

 cles, and Cowper's glands were developed 

 and an electric ejaculation test in the guinea 

 l)ig was devised (Moore, 1932, 1939). 

 Weights, sizes, cytologic structure, and mi- 

 totic activity in mouse seminal vesicles 

 were suggested as bioassay methods for an- 

 drogenic hormones (Deaneslv and Parkes. 

 1933). 



After th(> successful isolation and chemi- 

 cal characterization of androgens and estro- 

 gens from various sources, interest cen- 

 tered on the fundamental relationships of 

 androgens to normal develojjment, histo- 

 logic structure, and secretory activity of 

 the accessory glands in many species of 

 inainmals. The effects of estrogens and ges- 

 tagens and the competitive and synergistic 

 i'elationshii)s of steroid hormones were 



