Witcher J A, Freeman M E
Biol Reprod. 1985 May;32(4):834-9. doi: 10.1095/biolreprod32.4.834.
The influence of the proestrous surge of prolactin (Prl) on expression of feminine sexual behavior (lordosis) has been investigated. In the first experiment, proestrous rats were treated with a dopamine agonist, bromocriptine (CB-154; 100 micrograms at 1200, 1300, and 1600 h), which blocked the proestrous surge of Prl without affecting the preovulatory surge of luteinizing hormone. Such animals displayed depressed lordosis quotients (LQs) when compared to control animals at 2000 h on proestrus. However, in CB-154-treated animals given ovine Prl (10 I.U.) at 1400 h on proestrus, LQs were restored to control levels. Ovariectomized (OVX) rats primed with estradiol benzoate (EB; 2 micrograms for 2 days) produced surges of Prl that were similar in timing to those of proestrous. Once again, CB-154 treatment blocked this Prl surge and significantly depressed the LQ, whereas replacement with ovine Prl returned the LQ to control values. These results suggest that the Prl surge facilitates the expression of lordosis. Ovariectomized/adrenalectomized (ADX) and OVX/sham ADX rats were treated with EB (2 micrograms for 2 days) and tested for lordosis on Day 3. Adrenalectomized rats responded with lower levels of lordosis than did sham controls. Administration of progesterone (P4) to ADX rats on Day 3 enhanced the LQ compared to sham ADX values. CB-154 was ineffective in reversing the enhanced LQ, indicating that Prl may be acting through stimulation of adrenal progestins. These data taken together suggest that the proestrous surge of Prl contributes to the normal expression of feminine sexual behavior on proestrus.
已对动情前期催乳素（Prl）激增对雌性性行为（脊柱前凸）表达的影响进行了研究。在第一个实验中，给动情前期的大鼠注射多巴胺激动剂溴隐亭（CB - 154；在1200、1300和1600时各注射100微克），该药物可阻断Prl的动情前期激增，而不影响促黄体生成素的排卵前激增。与动情前期2000时的对照动物相比，这类动物的脊柱前凸商数（LQ）降低。然而，在动情前期1400时给经CB - 154处理的动物注射羊Prl（10国际单位）后，LQ恢复到对照水平。用苯甲酸雌二醇（EB；2微克，持续2天）预处理的去卵巢（OVX）大鼠出现的Prl激增在时间上与动情前期的相似。同样，CB - 154处理可阻断这种Prl激增并显著降低LQ，而用羊Prl替代则使LQ恢复到对照值。这些结果表明，Prl激增促进了脊柱前凸的表达。对去卵巢/肾上腺切除（ADX）和OVX/假手术ADX大鼠用EB（2微克，持续2天）进行处理，并在第3天测试其脊柱前凸情况。肾上腺切除的大鼠脊柱前凸水平低于假手术对照组。在第3天给ADX大鼠注射孕酮（P4），与假手术ADX组相比，LQ有所提高。CB - 154无法逆转升高的LQ，表明Prl可能是通过刺激肾上腺孕激素起作用。综合这些数据表明，Prl的动情前期激增有助于动情前期雌性性行为的正常表达。
