Opioidergic control of gonadotrophin secretion in the prepubertal gilt during restricted feeding and realimentation.
Opioidergic control of gonadotrophin secretion in the prepubertal gilt during restricted feeding and realimentation.
复制标题
在限制喂养和重新营养期间，阿片类药物控制青春期前后备母猪促性腺激素的分泌。
DOI：
10.1530/jrf.0.0910277
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
G. Foxcroft
中科院分区：
文献类型：
--
作者：
J. Cosgrove;P. Booth;G. Foxcroft
将经过7 d限饲至维持日粮的青春期前后备母猪分为4个处理之一；在09:00和17:00分别给予（RN组）和不给予（R组）阿片类拮抗剂盐酸纳洛酮（在09:30 h给予1 mg.kg-1，随后每小时间隔0.5 mg.kg-1，连续7 h）限制性喂养，或给予（ALN组）纳洛酮和不给予（AL组）纳洛酮进食至食欲。第8天早晚每隔10 min放血一次，用放射免疫法测定血浆LH、FSH和催乳素浓度。与R组相比，AL组黄体生成素平均浓度和最大浓度显著升高（P < 0.05），泌乳素浓度显著降低（P < 0.05），卵泡刺激素分泌差异不显著（P < 0.05）。纳洛酮显著抑制复饲后LH升高（P < 0.05）。同样，对促卵泡刺激素分泌没有显著影响。纳洛酮还显著抑制了限饲后备母猪泌乳素分泌（P < 0.05）。这些结果证实，重新喂食限制饲料的青春期前后备母猪会刺激黄体生成素分泌立即增加，而这种升高不是通过抑制内源性阿片能张力来介导的。相反，纳洛酮治疗似乎暴露了LH分泌的潜在抑制作用。在这个模型中，LH分泌的控制与FSH的控制不同。
Prepubertal gilts, having undergone a 7-day period of feed restriction to a maintenance ration, were allocated to one of 4 treatments; restricted feeding at 09:00 and 17:00 h for an 8th day both with (Group RN) and without (Group R) administration of the opioid antagonist naloxone hydrochloride (1 mg.kg-1 at 09:30 h followed by 0.5 mg.kg-1 at hourly intervals for 7 h), or feed to appetite with (Group ALN) and without (Group AL) naloxone administration. Gilts were bled at 10-min intervals on Day 8 from morning to evening feed and plasma LH, FSH and prolactin concentrations were measured by radioimmunoassay. Compared with Group R gilts, Group AL gilts exhibited significantly (P less than or equal to 0.05) higher mean and maximum LH concentrations and pulsatility, lower prolactin concentrations (P less than 0.05) but no significant difference in FSH secretion. Naloxone significantly depressed the increase in LH after re-feeding (Group ALN) (P less than 0.05). Once again there were no significant effects on FSH secretion. Naloxone also significantly depressed prolactin secretion in feed-restricted gilts (P less than 0.05). These results confirm that re-feeding of feed-restricted prepubertal gilts stimulates an immediate increase in LH secretion and that this elevation is not mediated via a suppression of inhibitory endogenous opioidergic tone. Rather, naloxone treatment appeared to expose a latent inhibition of LH secretion. The control of LH secretion is distinct from that of FSH in this model.