预水化对大鼠水利尿诱导的肾组织成分变化的影响。

Influence of prehydration on the changes in renal tissue composition induced by water diuresis in the rat.

作者信息

Hai M A, Thomas S

出版信息

J Physiol. 1969 Dec;205(3):599-618. doi: 10.1113/jphysiol.1969.sp008985.

DOI:10.1113/jphysiol.1969.sp008985

PMID:5361291

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC1348571/

Abstract

The composition of renal tissue was determined in rats before and immediately after intravenous infusion of dextrose (2.5 g/100 ml.) in amounts sufficient to administer a positive fluid load of 4% body weight over 2 hr. The rats were classified into three groups, according to the preinfusion urine osmolality: hydropaenia, normal and moderately diuretic (over 2400, 800-1500 and below 800 mu-osmoles/g H(2)O, respectively).2. In non-infused rats, the steepness of the corticomedullary osmolal gradient varied, due to differences in both water and solute (sodium and urea) contents, and was related to urinary osmolality. Whereas differences in medullary and papillary solute contents occurred between all three groups, papillary water content was significantly higher only in the moderately diuretic animals.3. Dextrose infusion caused the induction of water diuresis, the lowest urinary osmolalities being produced in the previously moderately diuretic animals.4. Dextrose infusion caused a considerable reduction in the steepness of the corticomedullary osmolal gradient in all rats, particularly in the previously hydropaenic animals, due to changes in both solute (sodium and urea) and water contents. Whereas reductions in medullary and papillary solute contents occurred in all three groups, there was no further increase in papillary water content from the already high values seen in the noninfused diuretic animals.5. Thus, dextrose infusion largely abolished any previous differences in tissue water content, whereas significant, though small, differences in osmolal (particularly urea) content persisted.6. These data are discussed in terms of changes and differences in endogenous antidiuretic hormone (A.D.H.) release.7. Changes in the magnitude and direction of the urinary-papillary urea concentration difference are discussed in terms of passive transport, with probable A.D.H.-induced changes in nephron urea permeability.

摘要

在大鼠静脉输注葡萄糖（2.5 g/100 ml）之前及输注后即刻，测定肾脏组织的组成。输注量足以在2小时内给予相当于体重4%的正性液体负荷。根据输注前尿渗透压，将大鼠分为三组：低血容量组、正常组和中度利尿组（分别为超过2400、800 - 1500和低于800毫渗摩尔/克H₂O）。
在未输注的大鼠中，由于水和溶质（钠和尿素）含量的差异，皮质髓质渗透压梯度的陡度有所不同，且与尿渗透压相关。虽然三组之间髓质和乳头溶质含量均有差异，但仅中度利尿动物的乳头含水量显著更高。
葡萄糖输注导致水利尿，先前中度利尿的动物产生的尿渗透压最低。
葡萄糖输注导致所有大鼠皮质髓质渗透压梯度的陡度显著降低，尤其是先前低血容量的动物，这是由于溶质（钠和尿素）和水含量的变化所致。虽然三组的髓质和乳头溶质含量均降低，但未输注的利尿动物乳头含水量本已很高，输注后并未进一步增加。
因此，葡萄糖输注在很大程度上消除了先前组织含水量的差异，而渗透压（尤其是尿素）含量仍存在显著但较小的差异。
根据内源性抗利尿激素（ADH）释放的变化和差异对这些数据进行了讨论。
根据被动转运以及可能由ADH诱导的肾单位尿素通透性变化，讨论了尿 - 乳头尿素浓度差的大小和方向的变化。