Scott Christopher J, Clarke Iain J, Tilbrook Alan J
Department of Physiology, Monash University, Vic., Australia; School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.
Domest Anim Endocrinol. 2008 May;34(4):440-50. doi: 10.1016/j.domaniend.2008.01.001. Epub 2008 Feb 14.
Testosterone and season influence mRNA expression for the opioid, enkephalin, in the preoptic area and hypothalamus of rams. Dynorphin is another opioid which has been shown to play a role in the control of reproductive function in females. We now report effects of season and testosterone on the expression of prodynorphin mRNA in the hypothalamus of the ram. Castrated adult Romney Marsh rams (5/group) received vehicle or testosterone propionate (i.m.) during either the 'breeding' season or 'non-breeding' season. Prodynorphin mRNA expression was quantified in the hypothalami by in situ hybridisation. Testosterone treatment increased prodynorphin mRNA expression in the supraoptic nucleus and the bed nucleus of the stria terminalis in the breeding season but not during the non-breeding season. Prodynorphin mRNA expression was also higher in the breeding season than in the non-breeding season in the caudal preoptic area, paraventricular nucleus and accessory supraoptic nucleus, irrespective of treatment. No effects of treatment were observed in any other regions of the hypothalamus. We conclude that testosterone and season regulate prodynorphin mRNA expression in a region-specific manner, which may influence seasonal changes in reproductive function.
睾酮和季节会影响公羊视前区和下丘脑内阿片样物质脑啡肽的mRNA表达。强啡肽是另一种阿片样物质，已被证明在雌性动物生殖功能的控制中发挥作用。我们现在报告季节和睾酮对公羊下丘脑前强啡肽原mRNA表达的影响。阉割后的成年罗姆尼沼泽公羊（每组5只）在“繁殖”季节或“非繁殖”季节接受载体或丙酸睾酮（肌肉注射）。通过原位杂交技术对下丘脑内的前强啡肽原mRNA表达进行定量分析。睾酮处理在繁殖季节增加了视上核和终纹床核中的前强啡肽原mRNA表达，但在非繁殖季节没有增加。无论是否接受处理，在尾侧视前区、室旁核和视上核旁核中，繁殖季节的前强啡肽原mRNA表达也高于非繁殖季节。在下丘脑的任何其他区域均未观察到处理的影响。我们得出结论，睾酮和季节以区域特异性方式调节前强啡肽原mRNA表达，这可能会影响生殖功能的季节性变化。
