Jacobson W, Wilkinson M, Gibson C J
Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
Brain Res Bull. 1988 May;20(5):643-9. doi: 10.1016/0361-9230(88)90225-0.
We have examined the effect of DSP4 treatment on PMSG-induced ovulation. A marked attenuation of the stimulatory effects of PMSG (7.5 I.U.) by DSP4 was evidenced by the significantly lower number of corpora lutea present in the ovaries of those animals which ovulated compared to controls. In addition, ovarian weight was lower in the DSP4 group. In a further experiment, we examined the effect of DSP4 on the induction of an LH surge by progesterone (P) in estradiol benzoate (EB) primed rats. DSP4 administration 2 hours prior to P eliminated the LH surge seen in controls. In view of our previous observations that DSP4 can interact with opioid receptors, we attempted to block its inhibitory effect on PMSG and EB/P stimulations. Coinjection of naloxone, an opioid antagonist, only partially prevented the influence of DSP4. It seems likely, therefore, that opioid receptors are not involved in the inhibitory effects of DSP4 described here. In further experiments, we studied the effects of DSP4 on spontaneous sexual maturation in female rats. DSP4 was administered (50 mg/kg, IP) on either day 5, day 23, day 29, or both day 24 and day 26 of life. Growth was inhibited and vaginal opening (VO) was significantly delayed in all except the day 29 group. However, VO occurred at the same body weight as the controls. By the end of the experiment, hypothalamic noradrenaline levels were not significantly different between control and DSP4-treated animals. The lack of an effect of DSP4 on the progression to puberty may be due to sufficient recovery of the central noradrenergic systems during the time course of the experiments.(ABSTRACT TRUNCATED AT 250 WORDS)
我们研究了DSP4处理对孕马血清促性腺激素（PMSG）诱导排卵的影响。与对照组相比，排卵动物卵巢中黄体数量显著减少，证明DSP4对PMSG（7.5国际单位）的刺激作用有明显减弱。此外，DSP4组的卵巢重量较低。在进一步的实验中，我们研究了DSP4对苯甲酸雌二醇（EB）预处理大鼠中孕酮（P）诱导促黄体生成素（LH）峰的影响。在给予P前2小时注射DSP4可消除对照组中出现的LH峰。鉴于我们之前观察到DSP4可与阿片受体相互作用，我们试图阻断其对PMSG和EB/P刺激的抑制作用。阿片拮抗剂纳洛酮的共同注射仅部分阻止了DSP4的影响。因此，阿片受体似乎不参与此处所述的DSP4的抑制作用。在进一步的实验中，我们研究了DSP4对雌性大鼠自发性性成熟的影响。在出生后第5天、第23天、第29天或第24天和第26天给予DSP4（50毫克/千克，腹腔注射）。除第29天组外，所有组的生长均受到抑制，阴道开口（VO）显著延迟。然而，VO发生时的体重与对照组相同。到实验结束时，对照组和DSP4处理组动物下丘脑去甲肾上腺素水平无显著差异。DSP4对青春期进程缺乏影响可能是由于实验过程中中枢去甲肾上腺素能系统充分恢复。（摘要截断于250字）
