Hematocrit modulates response of ANP to volume expansion in immature rats.
Hematocrit modulates response of ANP to volume expansion in immature rats.
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血细胞比容调节 ANP 对未成熟大鼠体积扩张的反应。
DOI：
10.1152/ajpregu.1990.258.3.r729
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Carey,RM
中科院分区：
文献类型：
--
作者：
Chevalier,RL;Thornhill,BA;Peach,MJ;Carey,RM
与成人相比，未成熟的肾脏对急性容量扩张（VE）的反应是利尿和排钠减少。其基本机制尚不清楚。尽管未成熟大鼠的红细胞压积（Hct）较低，但利尿和利钠作用减弱，这应增强对VE的反应。本研究旨在探讨心钠素（ANP）及其第二信使、环磷酸鸟苷（cGMP）和红细胞压积（Hct）在大鼠生后发育过程中对急性生理盐水VE（3%体重）肾脏反应的调节作用。实验分断乳前（P组）和断乳后（W组）两个阶段。在其他组中，通过VE前的等容交换输血，断奶前大鼠（PI组）的Hct升高，断奶后大鼠（WD组）的Hct降低。虽然对照血浆ANP浓度[（ANP）]在四组之间没有差异，但W组对VE的利尿和利钠反应的增加与[ANP]和尿cGMP排泄量（UcGMPV）的增加相关，高于P组（P <0.05）。PI组实验性Hct升高导致VE后[ANP]升高，但UcGMPV和利尿减少（P <0.05），而WD组Hct降低增加UcGMPV，但对[ANP]、利尿或尿钠排泄无显著影响。我们的结论是，ANP可能有助于增加肾反应VE与成熟和Hct调节ANP的释放，UcGMPV，和肾反应VE在出生后的成熟。
Compared with the adult, the immature kidney responds to acute volume expansion (VE) with reduced diuresis and natriuresis. The underlying mechanisms are poorly understood. Diuresis and natriuresis are blunted despite a lower hematocrit (Hct) in the immature rat, which should enhance the response to VE. The present study was designed to evaluate the role of atrial natriuretic peptide (ANP), its second messenger, guanosine 3',5'-cyclic monophosphate (cGMP), and Hct in the regulation of the renal response to acute saline VE (3% body wt) during postnatal development in rats. Anesthetized Sprague-Dawley rats were studied in the preweaning (group P) or postweaning period (group W). In additional groups, Hct was increased in preweaned rats (group PI) and decreased in postweaned rats (group WD) by isovolemic exchange transfusion before VE. Although control plasma ANP concentration [( ANP]) was not different among the four groups, the increased diuretic and natriuretic response to VE in group W was associated with a greater increase in [ANP] and urinary cGMP excretion (UcGMPV) than in group P (P less than 0.05). Experimental increases in Hct in group PI resulted in greater [ANP] after VE but a reduction in UcGMPV and diuresis (P less than 0.05), whereas decrease in Hct in group WD increased UcGMPV without a significant effect on [ANP], diuresis, or natriuresis. We conclude that ANP may contribute to the increasing renal response to VE with maturation and that Hct modulates ANP release, UcGMPV, and the renal response to VE in postnatal maturation.