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美国卫生研究院文献>The Journal of Physiology
>The effects of atrial natriuretic peptide and glucagon on proximal glomerulo-tubular balance in anaesthetized rats.
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The effects of atrial natriuretic peptide and glucagon on proximal glomerulo-tubular balance in anaesthetized rats.
1. The renal actions of ANP (average dose 30 ng kg-1 min-1 and glucagon (50 ng kg-1 min-1) were compared using fractional lithium reabsorption as the index of proximal reabsorption in groups of seven rats. Doses were chosen to cause similar increases in glomerular filtration rate (GFR). Time controls were included. 2. Glucagon raised GFR 32% and absolute proximal reabsorption (APR) 26% producing 81% effective proximal glomerulo-tubular balance (GTB) which was not significantly different from the 100% expected for perfect GTB. ANP raised GFR 33% and APR 10% indicating only 30% effective GTB (P less than 0.01). This was a significantly different effect from glucagon (P less than 0.005). 3. Sodium output increased 10-fold with ANP and 3-fold with glucagon. Filtration fraction increased 33% (P less than 0.04) above the pre-treatment value with ANP but was unchanged with glucagon. Plasma renin concentration was suppressed similarly by each hormone (46 and 36%, P less than 0.05, compared with pre-treatment values). 4. Despite a change in peritubular physical factors favouring reabsorption, there was almost complete attenuation of the increase expected in APR with the ANP-induced increase in GFR. In contrast, a similar change in GFR with glucagon resulted in an almost parallel increase in APR demonstrating maintenance of proximal GTB. 5. It is concluded that in the anaesthetized rat, ANP but not glucagon profoundly inhibits the increase in proximal reabsorption that normally follows an increase in filtered load. Such an action would contribute to the more potent natriuretic activity of ANP compared with glucagon.
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机译:1.用分数次锂重吸收作为近端重吸收的指标,比较七只大鼠组中ANP(平均剂量30 ng kg-1 min-1和胰高血糖素(50 ng kg-1 min-1)的肾脏作用。 2.胰高血糖素提高GFR 32%,绝对近端再吸收(APR)26%,产生有效的近端肾小管-肾小管平衡(GTB)81%与理想GTB的100%预期值不同; ANP将GFR提高33%,APR提高10%,表明有效GTB仅为30%(P小于0.01),与胰高血糖素的效果显着不同(P小于0.005)3.钠ANP的产量增加了10倍,胰高血糖素的产量增加了3倍。ANP的过滤率比治疗前的值增加了33%(P小于0.04),而胰高血糖素的则无变化。每种激素都同样抑制血浆肾素浓度(46和36%,P小于0.05,与h预处理值)。 4.尽管肾小管周围的物理因素发生了变化,有利于重吸收,但随着ANP引起的GFR增加,APR预期增加几乎完全减弱。相反,胰高血糖素的GFR发生类似变化,导致APR几乎平行增加,这表明近端GTB得以维持。 5.结论是,在麻醉的大鼠中,ANP而非胰高血糖素能显着抑制近端重吸收的增加,而后者通常是在过滤负荷增加后产生的。与胰高血糖素相比,这种作用将有助于ANP的利尿作用更强。
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