Forsberg G, Wiesenfeld-Hallin Z, Eneroth P, Södersten P
Department of Psychiatry, Karolinska Institute, Huddinge, Sweden.
Neurosci Lett. 1987 Oct 16;81(1-2):151-4. doi: 10.1016/0304-3940(87)90356-9.
The sensitivity to painful and sexual stimuli in male rats was markedly suppressed immediately after ejaculation and enhanced after the postejaculatory refractory period. The suppression of pain sensitivity induced by sexual activity was reversed, but sexual behavior was only slightly affected by intraperitoneal (i.p.) injection of the opioid antagonist naloxone (5 mg). Plasma concentrations of beta-endorphin-like immunoreactivity were unaffected by sexual activity. Injection of beta-endorphin (10 micrograms s.c.) markedly raised plasma concentrations of beta-endorphin-like immunoreactivity within 1 min of injection but did not affect the sensitivity to painful stimulation or the display of sexual behavior. It is suggested that while ejaculation may activate opioid receptor mechanisms, which affect the sensitivity to painful, but not sexual, stimuli, elevation of beta-endorphin in the blood does not affect the sensitivity to either sexual or painful stimuli in male rats.
雄性大鼠射精后对疼痛和性刺激的敏感性立即显著降低，而在射精后不应期后增强。性活动引起的痛觉敏感性抑制可被逆转，但腹腔注射阿片类拮抗剂纳洛酮（5毫克）仅对性行为有轻微影响。血浆中β-内啡肽样免疫反应性的浓度不受性活动影响。皮下注射β-内啡肽（10微克）在注射后1分钟内显著提高了血浆中β-内啡肽样免疫反应性的浓度，但不影响对疼痛刺激的敏感性或性行为表现。这表明，虽然射精可能激活阿片受体机制，影响对疼痛而非性刺激的敏感性，但血液中β-内啡肽水平的升高并不影响雄性大鼠对性或疼痛刺激的敏感性。
