Anoestrus in Farm Animals under Hot Environments.

炎热环境下农场动物的不发情。

• 批准号: 61560294
• 负责人: KANAI Yukio
• 金额: $ 1.34万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61560294/
• 关键词: Heat stress; Anoestrus; Ovarian activity; Hormonal secretion; シバヤギ; 発情; 暑熱環境; 高温ストレス; LHサージ; エストロジェン

A series of experiments was carried out to analyse the mechanisms by which heat stress suppresses oestrous behaviour and causes anoestrus in farm animals. In experiment 1, normally cycling goats were subjected to a three temperature treatments, 25゜C(control), 35゜C(mild hot) and 40゜C(severe hot), and their behavioural and hormonal responses were examined. Plasma concentrations of oestradiol during the follicular phase decreased as the temperature increased, whereas there were no significant variations in the plasma LH levels among the treatments. The decrease of oestradiol was much more pronounced under severe-stress conditions, resulting in a delay in the onset of oestrus or anoestrus. In experiment 2, ovariectomized animals were challenged to exgeneous oestradiol infusion which simulated the preovulatory levels of plasma oestradiol in intact animals. Neither the time of the infusion nor the amount of oestradiol infused to elicit normal oestrous behaviour was different under control an … More d sever-stress conditions, whereas the doses of oestradiol required to trigger the LH surge were significantly larger in heat stressed animals. In experiment 3, one of the groups of severe-hot was treated with bromocriptine in order to assess a possible involvement of the heat stress-induced hyperprolactinaemia in the reduction of the ovarian activity and/or the sensitivity of the hypothalamo-pituitary axis. The bromocriptine treatment completely suppressed prolaction in heat stressed animals. While the treatment failed to improve ovarian oestradiol secretion, the delay of LH surge in heat stressed animals was restored to a normal range. Based on these results, it was concluded that 1) the direct cause of anoestrus under heat stress condition might be the reduction of the ovarian oestradiol secretion, 2) the responsiveness of the hypothalamo-pituitary axis to the positive feedback effect of oestradiol was also desensitized due to heat stress-induced hyperprolactinamia, and 3) the hyperprolactinaemia, however, would not be a major cause of the reduction of ovarian oestradiol secretion. Less

进行了一系列实验来分析热应激抑制农场动物发情行为并导致不发情的机制。在实验1中，正常循环的山羊接受了25゜C（对照）、35゜C（轻度热）和40゜C（重度热）三种温度处理，并检查了它们的行为和激素反应。卵泡期雌二醇的血浆浓度随着温度升高而降低，而各处理之间血浆LH水平没有显着变化。在严重应激条件下，雌二醇的减少更为明显，导致发情或不发情的延迟。在实验2中，对切除卵巢的动物进行外源雌二醇输注，模拟完整动物的排卵前血浆雌二醇水平。在控制和严重应激条件下，输注时间和输注引起正常发情行为的雌二醇量都没有不同，而在热应激动物中，触发 LH 激增所需的雌二醇剂量明显更大。在实验3中，其中一组重热者接受溴隐亭治疗，以评估热应激诱发的高催乳素血症是否可能参与卵巢活性和/或下丘脑-垂体轴敏感性的降低。溴隐亭治疗完全抑制热应激动物的泌乳。虽然治疗未能改善卵巢雌二醇的分泌，但热应激动物的 LH 激增延迟恢复到正常范围。基于这些结果，得出以下结论：1）热应激条件下不发情的直接原因可能是卵巢雌二醇分泌减少，2）下丘脑-垂体轴对雌二醇正反馈作用的反应性也因热应激诱发的高催乳素血症而脱敏，3）高催乳素血症并不是导致雌二醇分泌减少的主要原因。 卵巢分泌雌二醇。较少的

项目成果

Yukio KANAI.: "Oestrous behaviour and plasma levels of pituitary gonadotrophins and ovarian steroids in heat-stressed goats."

Yukio KANAI：“热应激山羊的发情行为以及垂体促性腺激素和卵巢类固醇的血浆水平。”

Abdul-Latief Toleng: J. Reprod. Fert.

阿卜杜勒-拉蒂夫·托伦：J. Reprod。

Toleng ABDUL LATIEF.: "Effect of bromocriptine treatment on the secretion of pituitary gonadotrophins and ovarian steroids in heat-stressed cycling goats."

Toleng ABDUL LATIEF.：“溴隐亭治疗对热应激循环山羊垂体促性腺激素和卵巢类固醇分泌的影响。”

Yukio KANAI.: "Oestrus and some related phenomena in Shiba goats undre hot environmental conditions." Jpn. J. Zootech. Sci.58(9). 781-787 (1987)

Yukio KANAI.：“在炎热的环境条件下，柴山羊的发情和一些相关现象。”

Yukio Kanai: Jpn. J. Zootech. Sci.58. 781-789 (1987)

金井幸雄：日本。