Limonta P, Piva F, Maggi R, Dondi D, Motta M, Martini L
J Reprod Fertil. 1986 Mar;76(2):745-50. doi: 10.1530/jrf.0.0760745.
Morphine (200 micrograms/rat) was injected intraventricularly (i.v.t.) into normal and into long-term castrated (4 weeks) adult male rats. Animals were killed 10, 20, 40 and 60 min after treatment. In normal animals, the treatment with morphine resulted in a significant increase of serum prolactin concentrations at all time intervals considered. However, the i.v.t. injection of 200 micrograms morphine/rat into castrated rats did not exert any significant effect on prolactin release at any time interval considered. When morphine (200 micrograms/rat) was administered i.v.t. together with the specific opioid receptor blocker naloxone (7.5 or 15 micrograms/rat) the stimulatory effect of morphine on prolactin release was diminished at 10 min, and totally blocked at 20 min. Naloxone given alone did not influence serum prolactin concentrations. The results suggest that the presence of endogenous androgens is essential to permit the stimulatory effect of morphine on prolactin release.
将吗啡（200微克/只大鼠）经脑室注射到正常成年雄性大鼠和长期去势（4周）的成年雄性大鼠体内。在给药后10、20、40和60分钟处死动物。在正常动物中，在所有考虑的时间间隔，吗啡处理均导致血清催乳素浓度显著升高。然而，将200微克吗啡/只大鼠经脑室注射到去势大鼠体内，在任何考虑的时间间隔均未对催乳素释放产生任何显著影响。当将吗啡（200微克/只大鼠）与特异性阿片受体阻断剂纳洛酮（7.5或15微克/只大鼠）一起经脑室给药时，吗啡对催乳素释放的刺激作用在10分钟时减弱，在20分钟时完全被阻断。单独给予纳洛酮不影响血清催乳素浓度。结果表明，内源性雄激素的存在对于允许吗啡对催乳素释放产生刺激作用至关重要。
