Pan J T, Mai L M
Institute of Physiology, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China.
Life Sci. 1990;47(26):2443-50. doi: 10.1016/0024-3205(90)90489-e.
The roles of oxytocin and vasopressin on prolactin secretion were studied. Adult female Sprague-Dawley rats ovariectomized for two weeks and treated with a long-acting estrogen, polyestradiol phosphate for one week were used. Hormone administration and serial blood sampling were accomplished through indwelling intra-atrial catheters which were implanted two days before the experiment. Both oxytocin (20 micrograms/rat) and vasopressin (5 micrograms/rat) stimulated prolactin secretion within 10 min after injection and the effects were diminished by 30 min. In animals pretreated with a small dose of dopamine antagonist, sulpiride (1 microgram/rat), the effect of TRH on prolactin secretion was repeatedly shown to be potentiated. Same pretreatments with two different time intervals (30 and 60 min) between sulpiride and oxytocin/vasopressin administration, however, had no effect on oxytocin- or vasopressin-stimulated prolactin secretion. A vasopressin analog, 1-deamino-[D-Arg8]-vasopressin (dDAVP), with antidiuretic but no vasopressor activity was also used in the study. It was found that unlike vasopressin, dDAVP had no effect on prolactin secretion. In conclusion, both oxytocin and vasopressin can have a stimulatory effect on prolactin secretion when given in vivo. Unlike TRH, however, the action of oxytocin or vasopressin was not augmented by pretreatments of dopamine antagonist. The action of vasopressin on prolactin secretion may be a side effect of its vasopressor activity.
研究了催产素和加压素对催乳素分泌的作用。使用成年雌性Sprague-Dawley大鼠，这些大鼠已切除卵巢两周，并接受长效雌激素磷酸多雌二醇治疗一周。通过在实验前两天植入的心房留置导管进行激素给药和连续采血。催产素（20微克/只大鼠）和加压素（5微克/只大鼠）在注射后10分钟内均刺激催乳素分泌，且30分钟后作用减弱。在用小剂量多巴胺拮抗剂舒必利（1微克/只大鼠）预处理的动物中，促甲状腺激素释放激素（TRH）对催乳素分泌的作用反复显示得到增强。然而，在舒必利与催产素/加压素给药之间间隔两个不同时间（30分钟和60分钟）进行相同预处理，对催产素或加压素刺激的催乳素分泌没有影响。一种具有抗利尿但无升压活性的加压素类似物1-去氨基-[D-精氨酸8]-加压素（dDAVP）也用于该研究。发现与加压素不同，dDAVP对催乳素分泌没有影响。总之，催产素和加压素在体内给药时均可对催乳素分泌产生刺激作用。然而，与TRH不同，多巴胺拮抗剂预处理并不会增强催产素或加压素的作用。加压素对催乳素分泌的作用可能是其升压活性的副作用。
