394 



PHYSIOLOGY OF GONADS 



are secreted by the seminal vesicles, 

 whereas in the rat, citric acid is produced 

 by the seminal vesicles and fructose is 

 formed only in the dorsolateral prostate 

 and coagulating glands. 



D. METABOLISM OF THE PROSTATE AND 

 SEMINAL VESICLE 



The metabolism of the male accessory 

 reproductive glands, and the activity of 

 many enzymes therein, are influenced pro- 

 foundly by steroid hormones. In adult ani- 

 mals, excision of the testes results in a 

 rapid decline in the respiration, but not of 

 the anaerobic glycolysis, of slices of the 

 prostate gland of the dog (Barron and 

 Huggins, 1944), and of the rat prostate 

 (Homma, 1952; Nyden and Williams-Ash- 

 man, 1953; Bern, 1953; Rudolph and 

 Starnes, 1954; Butler and Schade, 1958) 

 and seminal vesicle (Rudolph and Samuels, 

 1949; Porter and Melampy, 1952; Rudolph 

 and Starnes, 1954j. The post-castrate fall 

 in oxygen consumption by these tissues can 

 be reversed by the administration of tes- 

 tosterone. The respiration of the epithelium 

 (but not of the muscle) of the guinea pig 

 seminal vesicle responds in a similar way to 

 androgen deprivation (Levey and Szego, 

 1955b). The stimulatory effect of testost- 

 erone on the respiration of the prostate 

 gland and seminal vesicle of castrated rats 

 is not prevented by the simultaneous ad- 

 ministration of hydrocortisone (Rudolph 

 and Starnes, 1954). 



The activity of a number of respiratory 

 enzymes in the rat prostate gland is de- 

 creased by castration to about the same 

 extent as the respiration of slices of this 

 tissue. This is true for the succinic and cy- 

 tochrome oxidase systems (Davis, Meyer 

 and McShan, 1949), and for fumarase, 

 aconitase, and malic dehydrogenase (Wil- 

 liams-Ashman, 1954). But the succinic oxi- 

 dase levels in two other androgen-sensitive 

 tissues are uninfluenced by castration, viz., 

 the epithelium of the guinea pig seminal 

 vesicle (Levey and Szego, 1955b), and the 

 levator ani muscle of the rat (Leonard, 

 1950). In the rat prostate, androgens have 

 little influence on the activity of the glyco- 

 lytic enzymes enolase and lactic (l(>hydro- 

 genase, and of the TPN-specific enzymes 

 which oxidize isocitrate, glucose 6-ph()s- 



i:)hate and 6-phosphogluconate (Williams- 

 Ashman, 1954; Rudolph, 1956). The enzy- 

 matic machinery responsible for the respira- 

 tion of the male accessory glands seems to 

 be similar to that of other mammalian tis- 

 sues (Barron and Huggins, 1946a, b; Nyden 

 and Williams-Ashman, 1953; Williams- 

 Ashman, and Banks, 1954b; Williams-Ash- 

 man, 1954, 1955; Levey and Szego, 1955a). 

 Glock and McLean (1955) have shown 

 that, as in most other mammalian tissues, 

 the levels of DPN in rodent prostate and 

 seminal vesicle are higher than those of 

 DPNH, whereas the content of TPNH is 

 much greater than that of TPN. 



Nyden and Williams-Ashman (1953) 

 found that the respiration-coupled synthe- 

 sis of long-chain fatty acids from acetate 

 by ventral prostate slices m viti'o was de- 

 pressed by castration to a greater extent 

 than the respiration, and could be restored 

 to normal levels by testosterone therapy. 

 Certain other synthetic reactions (the in- 

 corporation of P^--labeled inorganic phos- 

 phate into phospholipids, total nucleic 

 acids, and phosphoproteins) were less sen- 

 sitive to androgens under these conditions. 

 However, in experiments involving the in- 

 jection of P-^--labeled inorganic phosphate 

 into animals, the administration of andro- 

 gen increased the turnover of various acid- 

 insoluble phosphorus containing fractions. 

 Thus Levin, Albert and Johnson (1955) 

 observed that testosterone increases the 

 turnover of various phospholipids in the 

 lirostate gland and seminal vesicle. In the 

 seminal vesicle, Fleischmann and Fleisch- 

 mann (1952) found that the entry of P-'- 

 into the desoxyribonucleic acid fraction 

 was increased 100-fold by androgen ad- 

 ministered to castrate rats, whereas the 

 sjiecific radioactivity of the ribonucleic 

 acid was increased only 2-fold. Cytoplas- 

 mic basophilia in the rat seminal vesicle 

 (Melampy and Cavazos, 1953), and the 

 endoplasmic reticulum of the ventral pros- 

 tate gland (Harkin, 1957a), which are in- 

 timately associated with cytoi)lasmic ribo- 

 nucleic acid, are influenced profoundly by 

 androgenic hormones. 



Transamination bet^^■een glutamate and 

 cither pyruvate or a-ketoglutarate was 

 shown by Barron and Huggins (1946b) to 

 proceed rapidly in canine and human pros- 



