Dose-dependent effects of human prolactin on the immature hypophysectomized rat testis
| Autor: | David Dombrowicz, B. Sente, G Hennen, Jean Closset |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Male
endocrine system medicine.medical_specialty Biology Testicle Aromatase Endocrinology Reference Values Internal medicine Testis medicine Animals Humans Testosterone Cholesterol Side-Chain Cleavage Enzyme Sexual Maturation Hypophysectomy Dose-Response Relationship Drug Estradiol luteinizing hormone/choriogonadotropin receptor Rats Inbred Strains Organ Size Receptors LH Spermatozoa Prolactin Rats medicine.anatomical_structure biology.protein Pregnenolone Spermatogenesis Hormone medicine.drug |
| Zdroj: | Endocrinology. 130:695-700 |
| ISSN: | 1945-7170 0013-7227 |
| Popis: | We have studied dose-dependent effects of highly purified human PRL (39 IU/mg) on the testis of immature (22-day-old) hypophysectomized rats daily supplemented for 7 days with 2, 10, or 30 micrograms hormone. Dose-dependent stimulation was observed for all parameters: testis weight (1.6- and 2-fold above control for 10 and 30 micrograms PRL), basal and hCG-stimulated testosterone (14- and 21-fold), intratesticular testosterone (7- and 21-fold) and estradiol (1.2- and 1.5-fold), LH receptor concentration (1.8- and 2.5-fold), in vitro pregnenolone production by cholesterol side-chain cleavage enzyme (3-, 5- and 7-fold), and aromatase activity (2.1- and 2.4-fold). The number of Leydig cells exhibiting immunoreactivity toward anti-P450scc, anti-P450(17 alpha), and anti-3 beta-hydroxysteroid dehydrogenase antibodies also underwent a dose-dependent increase (under conditions revealing many immunopositive cells in hypox control animals). The respective increases were 8- to 14-fold for anti-P450scc and P450(17 alpha) and 1.5- to 2-fold for anti-3 beta-hydroxysteroid dehydrogenase. The number of germ cells and the percentage of tubular sections containing late pachytene spermatocytes as most advanced stages of spermatogenesis were subject to similar dose-dependent effects. These results suggest that during puberty PRL stimulates testicular function by promoting multiplication and differentiation of Leydig cells (acting at various steps of steroidogenesis and on tissue responsiveness to LH) and germ cells. |
| Databáze: | OpenAIRE |
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