| Abstract: | Pregnenolone, androstenedione and testosterone were identified by RIA in tissue homogenates of the pronephric region, the opisthonephros, the gonads and in plasma samples from male and female immature and mature adult brook lampreys. Additionally, hydroxysteroid dehydrogenase activity was determined spectrophotometrically in homogenates from the same tissues of mature and spent adult brook lampreys employing pregnenolone, testosterone or 3β,17β-dihydroxy-5β-androstane as substrates. The steroid levels show differences corresponding to developmental stages, tissues and sex. Remarkable quantities of testosterone were measured in the testicular tissue homogenates, in homogenates obtained from the pronephric region and in the serum. |
