Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey; Department of Biosciences, University of Wah, Wah Cantt, Pakistan.
Department of Physiology, Faculty of Veterinary Medicine, Uludag University, Bursa 16059, Turkey.
Brain Res. 2018 Nov 15;1699:150-157. doi: 10.1016/j.brainres.2018.08.020. Epub 2018 Aug 18.
Brain histamine holds a key position in the regulation of behavioral states, biological rhythms, body weight, energy metabolism, thermoregulation, fluid balance, stress and reproduction in female animals. However, it is not clear whether central histamine exerts any effect on hypothalamic-pituitary-testicular in male rats and if so, the involvement of type of central histamine receptors. The current study was designed to determine the effect of centrally administrated histamine on plasma gonadotropin hormone-releasing hormone (GnRH), luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone level, and sperm parameters, and to show the mediation of the central histaminergic H1, H2 and H3/H4 receptors on histamine-evoked hormonal and sperm parameters' effects. Studies were performed in male Sprague-Dawley rats. A total of 50 or 100 nmol doses of histamine were injected intracerebroventricularly (icv). 100 nmol dose of histamine significantly caused increases in plasma GnRH, LH, FSH and testosterone levels of animals, but not 50 nmol dose of histamine. Moreover, central pretreatment with chlorpheniramine, histaminergic H1 receptor antagonist (100 nmol), ranitidine and histaminergic H2 receptor antagonist (100 nmol) completely prevented histamine evoked increase in plasma GnRH, LH, FSH and testosterone levels, while thioperamide, histaminergic H3/H4 receptor antagonist (100 nmol) pretreatment failed to reverse sex hormones responses to histamine. Both central histamine treatment alone and central histamine treatment after central histaminergic receptors antagonists' pretreatments did not alter any sperm parameters in rats. In conclusion, our findings show that centrally administered histamine increases plasma GnRH, LH, FSH and testosterone levels of conscious male rats without change any sperm parameters. Moreover, according to our findings, central histaminergic H1, and H2 receptors mediate these histamine-induced effects.
脑组胺在调节动物的行为状态、生物节律、体重、能量代谢、体温调节、体液平衡、应激和生殖等方面具有重要作用。然而，目前尚不清楚中枢组胺是否对雄性大鼠的下丘脑-垂体-睾丸轴产生影响，如果有影响，其涉及哪种中枢组胺受体。本研究旨在确定中枢给予组胺对血浆促性腺激素释放激素（GnRH）、黄体生成素（LH）、卵泡刺激素（FSH）和睾酮水平以及精子参数的影响，并显示中枢组胺能 H1、H2 和 H3/H4 受体对组胺诱发的激素和精子参数效应的介导作用。研究在雄性 Sprague-Dawley 大鼠中进行。共给予 50 或 100nmol 剂量的组胺脑室给药（icv）。100nmol 剂量的组胺显著引起动物血浆 GnRH、LH、FSH 和睾酮水平升高，但 50nmol 剂量的组胺没有引起这种作用。此外，中枢给予氯苯那敏（组胺 H1 受体拮抗剂，100nmol）、雷尼替丁（组胺 H2 受体拮抗剂，100nmol）预处理完全阻断了组胺引起的血浆 GnRH、LH、FSH 和睾酮水平升高，而噻庚啶（组胺 H3/H4 受体拮抗剂，100nmol）预处理不能逆转激素对组胺的反应。中枢组胺单独处理以及在中枢组胺能受体拮抗剂预处理后给予中枢组胺处理均未改变大鼠的任何精子参数。总之，我们的研究结果表明，中枢给予组胺可增加清醒雄性大鼠的血浆 GnRH、LH、FSH 和睾酮水平，而不改变任何精子参数。此外，根据我们的发现，中枢组胺能 H1 和 H2 受体介导了这些组胺诱导的作用。
