Effect of melatonin injected into the third ventricle on growth hormone secretion in Holstein steers
Effect of melatonin injected into the third ventricle on growth hormone secretion in Holstein steers
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DOI：
10.1292/jvms.68.1075
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发表时间：
2006-10-01
影响因子：
1.2
通讯作者：
Hodate, Koichi
中科院分区：
文献类型：
--
作者：
Kasuya, Etsuko;Kushibiki, Shiro;Hodate, Koichi
在清醒的荷斯坦肉牛上研究了第三脑室注射褪黑激素（MEL）对生长激素（GH）分泌的影响。根据脑室造影，将不锈钢套管立体定位植入3V。在Exp. 1，通过套管将三个剂量的MEL（100、300或600 μ g）注射到3V中，并测定注射后的GH浓度。在Exp. 2、侧脑室（icv）和静脉（iv）分别注射MEL（100 μ g）和GH释放激素（GHRH; 0.25 μ g/kg体重），观察MEL对GHRH诱导的GH释放的影响。icv注射MEL在100 μ g时显著刺激GH释放。100 μ g MEL可持续增加GH浓度。静脉注射GHRH显著增加GH释放。注射MEL不改变GHRH诱导的GH释放。这些结果表明，MEL刺激GH分泌可能通过下丘脑在牛。关键词：牛，褪黑激素，促生长轴，立体定向，第三脑室。
The effects of melatonin (MEL) injection into the third ventricle (W) on growth hormone (GH) secretion were investigated in conscious Holstein steers. A stainless steel cannula was stereotaxically implanted in the 3V based on the ventriculogram. In Exp. 1, three doses of MEL (100, 300 or 600 mu g) were injected into the 3V through the cannula and the GH concentration after the injection was determined. In Exp. 2, intracerebroventricular (icv) and intravenous (iv) injections of MEL (100 jig) and GH-releasing hormone (GHRH; 0.25 mu g/kg body weight), respectively, were performed simultaneously to examine the effect of MEL on GHRH-induced GH release. The icv injection of MEL significantly stimulated GH release at 100 mu g. The increase in GH concentrations by 100 mu g of MEL was persistent. Intravenous injection of GHRH dramatically increased GH release. The injection of MEL did not alter GHRH-induced GH release. These results suggest that MEL stimulates GH secretion possibly through the hypothalamus in cattle. KEY WORDS: cattle, melatonin, somatotropic axis, stereotaxic, third ventricle.