Niklowitz P, Böckers T M, Lerchl A
Institute for Reproductive Medicine, The University, Münster, Germany.
J Pineal Res. 1996 Nov;21(4):231-8. doi: 10.1111/j.1600-079x.1996.tb00291.x.
The effects of exogenous melatonin on gonadal function and on the endogenous melatonin profiles of male and female Djungarian hamsters were investigated. Daily afternoon subcutaneous injections of melatonin (50 micrograms) in hamsters kept in long photoperiods (LD 16:8) led to gonadal inhibition in all the treated females (n = 13) but in only 2 of 13 males within the treatment period of 8 weeks (uteri: 244 +/- 11 mg in controls vs. 79 +/- 4 mg in treated hamsters, P < 0.001; ovaries: 13.6 +/- 0.6 mg in controls vs. 7.9 +/- 0.7 mg in treated hamsters, P < 0.001; testes: 1,021 +/- 54 mg in controls vs. 732 +/- 100 mg in treated hamsters, P < 0.05; and accessory glands: 641 +/- 38 mg in controls vs. 548 +/- 70 mg in treated hamsters, P > 0.05). These results indicate that there are some circumstances under which the gonadal responses of the reproductive organs of male and female Djungarian hamsters differ. Interestingly, pineal concentrations of melatonin were found to be significantly higher in males (P < 0.01), possibly indicating a more robust endogenous supply with the hormone, whereas serum melatonin levels were not significantly different between males and females. However, the subcutaneous injection of melatonin (5, 25, and 125 micrograms) exerted no acute effect on the endogenous, circadian melatonin-profile, independent of dosage and sex.
研究了外源性褪黑素对雄性和雌性中仓鼠性腺功能以及内源性褪黑素水平的影响。在长光照周期（LD 16:8）下饲养的仓鼠中，每天下午皮下注射褪黑素（50微克），在为期8周的治疗期内，所有接受治疗的雌性仓鼠（n = 13）均出现性腺抑制，但13只雄性仓鼠中只有2只出现性腺抑制（子宫：对照组为244±11毫克，治疗组仓鼠为79±4毫克，P < 0.001；卵巢：对照组为13.6±0.6毫克，治疗组仓鼠为7.9±0.7毫克，P < 0.001；睾丸：对照组为1,021±54毫克，治疗组仓鼠为732±100毫克，P < 0.05；附属腺体：对照组为641±38毫克，治疗组仓鼠为548±70毫克，P > 0.05）。这些结果表明，在某些情况下，雄性和雌性中仓鼠生殖器官的性腺反应存在差异。有趣的是，发现雄性仓鼠松果体中的褪黑素浓度显著更高（P < 0.01），这可能表明其体内该激素的内源性供应更为充足，而雄性和雌性仓鼠的血清褪黑素水平并无显著差异。然而，皮下注射褪黑素（5、25和125微克）对内源性昼夜褪黑素水平没有急性影响，且与剂量和性别无关。
