Changes in testicular and serum hormone concentrations in the male rat following treatment with m-dinitrobenzene.
m-Dinitrobenzene (m-DNB)-induced testicular atrophy has been attributed to a direct effect upon the germinal epithelium. However, such degenerative changes in the germinal epithelium should induce shifts in the testicular hormonal milieu, which would in turn alter the hypothalamic-pituitary gonadal axis in general. This study evaluated the endocrine status of male rats (killed 3 hr, 24 hr, 1 week, and 2 weeks) following a single oral dose of m-DNB (32 mg m-DNB/kg). Serum and pituitary leuteinizing hormone, follicle-stimulating hormone (FSH), and protactin and hypothalamic gonadotropin-releasing hormone (GnRH) concentrations were determined. Testosterone and androgen-binding protein concentrations in serum, interstitial fluid, seminiferous tubule fluid, and caput epididymis were also determined. In vitro basal and hCG-stimulated testosterone release was determined in the decapsulated testis. Results of the present study indicate that pituitary hormone concentrations and hypothalamic GnRH were unaffected after a single oral dose of m-DNB. Serum FSH was elevated at 2 weeks. There was a transient decrease in serum testosterone at 24 hr, which returned to control values at 1 and 2 weeks. Interstitial fluid, seminiferous tubule fluid, and caput epididymal testosterone concentrations were increased at 1 and 2 weeks. Basal testosterone release in vitro was increased at 2 weeks, while hCG-stimulated testosterone release was increased at 1 and 2 weeks. Androgen-binding protein concentrations in serum and interstitial fluid were increased at 1 and 2 weeks. Androgen-binding protein was increased at 24 hr and 1 week in seminiferous tubule fluid, but returned to control concentrations by 2 weeks. However, the total tubular content of androgen-binding protein was dramatically decreased at 2 weeks. Androgen-binding protein in the caput epididymis was unaltered following m-DNB treatment. These data demonstrate that m-DNB exerts a direct effect on the testes and not through alterations in hypothalamic and pituitary control of gonadal function.
D000818:Animals; D004136:Dinitrobenzenes / Q000494:pharmacology*; D005640:Follicle Stimulating Hormone / Q000032:analysis / Q000097:blood; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis / Q000097:blood; D006728:Hormones / Q000032:analysis* / Q000097:blood; D007031:Hypothalamus / Q000032:analysis / Q000187:drug effects; D007986:Luteinizing Hormone / Q000032:analysis / Q000097:blood; D008297:Male; D009578:Nitrobenzenes / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D010902:Pituitary Gland / Q000032:analysis / Q000187:drug effects; D011388:Prolactin / Q000032:analysis / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D013737:Testis / Q000032:analysis / Q000187:drug effects*
D004136:Dinitrobenzenes; D006728:Hormones; D009578:Nitrobenzenes; D007987:Gonadotropin-Releasing Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C017906:3-dinitrobenzene