ACCESSORY MAMMALIAN REPRODUCTIVE GLANDS 



397 



into two distinct phases (Gotterer and 

 AVilliams-Ashman, 1957). The first of these 

 requires a metal ion such as Mn++, is in- 

 hibited by Versene, and does not necessarily 

 involve the precipitation of insoluble ma- 

 terial. The second phase, which is insensi- 

 tive to the action of metal chelating agents, 

 is inhibited by mercuric ions and leads to 

 the formation of a coagulum. The coagu- 

 lated material is protein in nature. 



Further fractionation of the vesicular 

 secretion by Speyer (1959) led to the iso- 

 lation of a heat-stable protein, coagulino- 

 gen, which is the precursor of the insoluble 

 material of the vaginal plug, but is not 

 clotted by vesiculase. Speyer (1959) iso- 

 lated another, heat-labile protein from 

 vesicular secretion which he designated 

 procoagulase, and which is converted into 

 a clotting enzyme coagulase by the action 

 of vesiculase. The coagulation of the semi- 

 nal vesicle secretion by the prostatic en- 

 zyme vesiculase thus seems to take place 

 by the following reactions: 



„ , Vesiculase „ , 



rrocoagulase > Coagulase 



Coagulinogen °^^" '^^^ — ^ Coagulated protein 



Only the first reaction is inhibited by 

 Versene. 



Partial purification of vesiculase has 

 l>een achieved (Gotterer, Ginsburg, Schul- 

 man. Banks and Williams-Ashman, 1955). 

 Vesiculase is quite distinct from another 

 enzyme in the secretion of the coagulating 

 gland of guinea pigs which hydrolyzes, in- 

 ter alia, tosyl-L-arginine methyl ester 

 (TAMe) (Gotterer, Banks and Williams- 

 Ashman, 1956). Unlike thrombin, vesicu- 

 lase does not hydrolyze TAMe and does not 

 clot fibrinogen. The dissimilarity between 

 the coagulation of blood and of semen is 

 further borne out by the failure of thrombin 

 to clot the proteins of the vesicular secre- 

 tion, and by the inability of TA]\Ie (which 

 depresses the action of thrombin) to inhibit 

 vesiculase action. 



Electrical stimulation of the head of the 

 guinea pig induces ejaculation without 

 voiding of either urine or feces (Batelli, 

 1922). Ejaculates obtained in this manner 

 from normal, sexually mature guinea pigs 

 coagulate rapidly. After castration, the se- 

 men is no longer coagulable, but becomes 



so a few days after treatment with andro- 

 gens (Moore and Gallagher, 1930). This 

 "electric ejaculation test" can be used as 

 an indicator for androgenic activity (c/. 

 Sayles, 1939, 1942). 



It is generally believed that human se- 

 men is ejaculated as a fluid, and then co- 

 agulates (Lane-Roberts, Sharman, Walker 

 and Wiesner, 1939; Joel, 1942; Huggins 

 and Neal, 1942; Lundquist, 1949), although 

 some authors state that it is emitted in a 

 gelatinous form (Pollak, 1943; Hammen, 

 1944; Oettle, 1954). But there is no doubt 

 that the semen from normal men subse- 

 quently liquifies if kept at room tempera- 

 ture.^ Human semen possesses strong fi- 

 brinolytic activity (Huggins and Neal, 

 1942; Harvey, 1949; Ying, Day, Whitmore 

 and Tagnon, 1956). The prostate gland of 

 men secretes a proteolytic enzyme, fibrino- 

 lysin, which is probably responsible for the 

 phenomenon of liquefaction. Prostatic fi- 

 brinolysin is produced in large amounts by 

 certain cancers of the prostate in man, and 

 seems to enter the circulation since there 

 is a pronounced bleeding tendency in such 

 patients (Tagnon, Schulman, Whitmore 

 and Leone, 1953; Scott, Matthews, Butter- 

 worth and Frommeyer, 1954; Swan, Wood 

 and Owen, 1957). Canine semen, which 

 does not clot, contains little fibrinolysin, 

 but is rich in another proteolytic enzyme, 

 fibrinogenase, which hydrolyzes fibrinogen. 

 Little fibrinogenase is present in human 

 semen (Huggins and Neal, 1942). The pres- 

 ence of related proteolytic enzymes in the 

 secretions of the male accessory glands is 

 described above. 



^ Louis Nicolas Vauquelin published the first 

 paper on the chemistry of seminal fluid (Vau- 

 quelin, 1791). This remarkable study includes a 

 detailed and accurate account of the liquefaction 

 of human semen which is quite unexcelled by later 

 writings. It also describes the formation, in ejacu- 

 lates which had stood for three or four days, of 

 "cristaux transparens, d'environ une hgne de long, 

 tres-minces, et qui se croisent souvent de maniere 

 a representer les rayons d'une roue. Ces cristaux 

 isoles nous ont offer, a I'aide d'un verre grossissant, 

 la forme d'un solide a quatre pans, termines par 

 des pyramides tres-allongees, a quatre faces." Al- 

 though Vauquelin believed that these crystals were 

 composed of calcium phosphate, Mann (1954a) 

 has pointed out that he had, in reality, obser\ed 

 the deposition of spermine phosphate in aged 

 semen. 



