Effects of melatonin, serotonin and n-acetylserotonin on the production of steroids by duck testicular homogenates

• Published in: Steroids Vol. 18; no. 1; pp. 25 - 37
• Main Authors: Cardinali, Daniel P., Rosner, Jorge M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.1971
• Subjects: 17-Hydroxycorticosteroids - metabolism; Androstanes - metabolism; Animals; Chromatography, Paper; Crystallization; Dehydroepiandrosterone - metabolism; Ducks; Hydroxysteroid Dehydrogenases - antagonists & inhibitors; In Vitro Techniques; Ketosteroids - metabolism; Male; Melatonin - pharmacology; Mixed Function Oxygenases - antagonists & inhibitors; Oxidoreductases - antagonists & inhibitors; Progesterone - metabolism; Serotonin - pharmacology; Steroids; Testis - drug effects; Testis - metabolism; Testosterone - biosynthesis
• ISSN: 0039-128X; 1878-5867
• DOI: 10.1016/S0039-128X(71)80168-X

A progonadal function of the pineal gland has been previously established in the duck and in order to determine whether melatonin has a direct effect on the “in vitro” production of steroids by the duck testis the following experiments were performed. Duck testicular homogenates were incubated with labeled progesterone, androst-4-en-3, 17-dione and 3β-hydroxyandrost-5-en-17-one. Progesterone-4- 14C was converted to 17α-hydroxypregn-4-en-3, 20-dione, androst-4-en-3, 17-dione, testosterone, 20α-hydroxypregn-4-en-3-one, 17α, 20α-dihydroxypregn-4-en-3-one, 6β-hydroxypregn-4-en-3, 20-dione, 5α-pregnane-3, 20-dione and 5α-androstane-3, 17-dione. Androst-4-en-3, 17-dione-4- 14C was metabolized to testosterone and 5α-androstane-3, 17-dione while 3β-hydroxyandrost-5-en-17-one-4- 14C was converted to androst-4-en-3, 17-dione, testosterone and 5α-androstane-3, 17-dione. Melatonin (2 m μ moles/ml of incubation medium) inhibited the activity of the 3β-hydroxysteroid dehydrogenase-4-5-ene isomerase system, 17α-hydroxylase, 6β-hydr oxylase and 5α-, 17β(C19 steroid)-and 20α-reductase. No effects of serotonin and N-acetylserotonin were observed when doses below 200 m μ moles/ml were utilized. Although the pineal gland has a progonadal function in the duck, a specific inhibitory effect of melatonin on the testicular production of steroids could be demonstrated.