Chaturvedi C M, Cornett L E, Koike T I
Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock 72205, USA.
Peptides. 1997;18(9):1383-8. doi: 10.1016/s0196-9781(97)00190-3.
Osmotic stress stimulates the release of the avian hypothalamic neuropeptide arginine vasotocin (AVT) into the peripheral circulation. We conducted the present study to investigate the effects of salt-loading on AVT secretion and AVT gene expression in specific hypothalamic nuclei in chickens. White Leghorn chickens were provided food ad lib and either water or 2% NaCl to drink. Both plasma osmolality and plasma AVT levels were significantly increased in chickens that drank 2% NaCl for either two or four days compared to that in chickens that drank water. Results from in situ hybridization analysis demonstrated an increase in the number of neurons expressing AVT mRNA in the supraoptic (SON) and paraventricular nuclei (PVN) in chickens provided 2% NaCl to drink compared to chickens that were provided water to drink. The number of grains per neuron increased in the PVN, but not in the SON of osmotically stimulated birds. Thus, increased osmolality resulting from ingestion of hypertonic saline is an effective stimulus to increase hypothalamic AVT mRNA content in chickens.
渗透应激刺激鸟类下丘脑神经肽精氨酸加压催产素（AVT）释放进入外周循环。我们进行本研究以调查盐负荷对鸡特定下丘脑核团中AVT分泌及AVT基因表达的影响。为白来航鸡提供随意采食的食物，并提供水或2% NaCl溶液供其饮用。与饮用清水的鸡相比，饮用2% NaCl溶液两天或四天的鸡的血浆渗透压和血浆AVT水平均显著升高。原位杂交分析结果表明，与饮用清水的鸡相比，饮用2% NaCl溶液的鸡的视上核（SON）和室旁核（PVN）中表达AVT mRNA的神经元数量增加。在渗透刺激的鸡的PVN中，每个神经元的颗粒数增加，但在SON中未增加。因此，摄入高渗盐水导致的渗透压升高是增加鸡下丘脑AVT mRNA含量的有效刺激因素。
