Stallone J N, Braun E J
Am J Physiol. 1985 Dec;249(6 Pt 2):F842-50. doi: 10.1152/ajprenal.1985.249.6.F842.
Recently developed radioimmunoassay (RIA) techniques were employed in a quantitative investigation of the renal actions of the avian antidiuretic hormone arginine vasotocin (AVT) in the conscious domestic fowl. Constant intravenous infusion of AVT at doses of 0.125-1.00 ng X kg-1 X min-1 was used to produce plasma AVT (PAVT) concentrations (verified by RIA) over the entire range of physiological PAVT levels in the domestic fowl. Comparison of the dose-response relationships between PAVT and glomerular and tubular mechanisms of antidiuresis revealed that tubular mechanisms are of primary importance and glomerular mechanisms of secondary importance in the conservation of water by the avian kidney. The greatest proportion of the total AVT-induced reduction in renal water excretion occurred at low physiological PAVT levels (less than 5 microU/ml), prior to any significant reduction in glomerular filtration rate (GFR), and appeared to be the exclusive result of tubular mechanisms of antidiuresis. At high PAVT levels (5-16 microU/ml), glomerular and tubular mechanisms overlapped, and their effects on water conservation could not be separated. Although GFR was reduced by nearly 30% at the highest dose of AVT, only minor additional amounts of water were conserved by the combined actions of glomerular and tubular mechanisms. Thus glomerular mechanisms appear to have only a minor secondary effect on water-conserving ability of the avian kidney.
最近开发的放射免疫分析（RIA）技术被用于对清醒家鸡体内鸟类抗利尿激素精氨酸加压催产素（AVT）的肾脏作用进行定量研究。以0.125 - 1.00 ng X kg-1 X min-1的剂量持续静脉输注AVT，以产生涵盖家鸡生理AVT水平整个范围的血浆AVT（PAVT）浓度（通过RIA验证）。比较PAVT与抗利尿的肾小球和肾小管机制之间的剂量反应关系表明，在鸟类肾脏保水过程中，肾小管机制起主要作用，而肾小球机制起次要作用。在肾小球滤过率（GFR）出现任何显著降低之前，在低生理PAVT水平（低于5微单位/毫升）时，AVT诱导的肾脏水排泄减少总量中最大比例出现，并且似乎是抗利尿肾小管机制的唯一结果。在高PAVT水平（5 - 16微单位/毫升）时，肾小球和肾小管机制重叠，它们对保水的影响无法分开。尽管在最高剂量的AVT作用下GFR降低了近30%，但通过肾小球和肾小管机制的联合作用仅额外保留了少量水分。因此，肾小球机制似乎对鸟类肾脏的保水能力仅具有较小的次要影响。
