Studies of Androgen Production by the Rat: Testosterone and Androstenedione Content of Blood1

Abstract

Testosterone and androstenedione were identified in pools of testicular and adrenal venous blood of the rat by chromatographic mobility as free steroids and as derivatives and by retention time in gas-liquid chromatography. A double isotope derivative method was developed for the estimation of testosterone in blood using C14 steroids as internal standards and acetic anhydride- 1-H3 as indicator; androstenedione was reduced with NaBH4 and measured as testosterone. The nonspecific blanks for testosterone and androstendedione were 0.006 [plus or minus] 0.006 (SD) and 0.10 [plus or minus] 0.09 (SD) [mu]g/100 ml blood, respectively. The testosterone concentration in the testicular venous blood of untreated rats was 4.2 [plus or minus] 0.56 (SE) [mu]g/100 ml and of ethersaline treated animals was 1.4 [plus or minus] 0.42 (SE) [mu]g/100 ml; the significant difference in the testosterone concentration between these 2 groups (P<0.01) suggests that the stress of ether administration lowered endogenous gonadotropin production. Both testosterone and androstenedione secretion increased following treat?ment with HCG [human chorionic gonadotropin].