Gauquelin G, Schiffrin E L, Garcia R, Entresangles M, Cantin M, Gharib C
Lab. Physiol. Fac. Méd. Grange-Blanche, Lyon, France.
Life Sci. 1988;43(23):1905-12. doi: 10.1016/s0024-3205(88)80008-0.
We observed a significant increase in plasma atrial natriuretic factor (ANF) in antiorthostatic hypokinetic suspension (AOH) rats after 2 h of suspension when the experiment was made during day. Plasma ANF was investigated in relation to renal glomerular ANF receptors during AOH at night. The aim of this study was 1) to compare the day and night ANF responses to AOH 2) to determine whether the renal glomerular ANF receptors are involved. The rats were divided into 2 groups: i) 24 population cage (PC), and ii) 24 were attached by the tail (Morey's model) and remained in the horizontal position (attached horizontal-AH). Six AH were suspended (30 degrees) for 2 hours (AOH) and sacrificed with the controls: PC and AH (12.00h). The same experiment was made during the night (24.00h). A significant increase in plasma ANF was found in both AOH and AH after 2 h of suspension during day and night (19 +/- 2.3 pg/ml vs 9 +/- 0.95 and 18 +/- 3 pg/ml vs 10.2 +/- 1.8 respectively). PC rats had a significantly higher ANF level (38 +/- 5 pg/ml) than AH or AOH. The glomerular ANF receptor population was slightly lower in AOH than in AH (429 +/- 12 fmol/mg protein vs 507 +/- 5) during day. During night, a significantly lower number of ANF receptors was observed in AOH animals as compared to AH (168 +/- 2 fmol/mg protein vs 455 +/- 3). A decrease in glomerular receptors was also noted in PC during night. Day-time head-down tilt, bed rest or head-out water induced a natriuretic and diuretic response, whereas the normal recumbency at night does not lead to such effects. We conclude that the natriuretic and diuretic response not observed during night was associated with elevated plasma ANF levels and decreased ANF receptor density.
我们观察到，在白天进行实验时，抗直立性低动力悬吊（AOH）大鼠悬吊2小时后血浆心钠素（ANF）显著增加。在夜间AOH期间，研究了血浆ANF与肾小球ANF受体的关系。本研究的目的是：1）比较白天和夜间AOH时ANF的反应；2）确定肾小球ANF受体是否参与其中。大鼠分为两组：i）24只群养笼养（PC）；ii）24只通过尾巴固定（莫雷模型）并保持水平姿势（固定水平-AH）。6只AH大鼠悬吊（30度）2小时（AOH），然后与对照组（PC和AH，12:00）一起处死。夜间（24:00）进行相同实验。在白天和夜间悬吊2小时后，AOH和AH大鼠血浆ANF均显著增加（分别为19±2.3 pg/ml对9±0.95以及18±3 pg/ml对10.2±1.8）。PC大鼠的ANF水平（38±5 pg/ml）显著高于AH或AOH大鼠。白天，AOH大鼠肾小球ANF受体数量略低于AH大鼠（429±12 fmol/mg蛋白对507±5）。夜间，与AH大鼠相比，AOH大鼠的ANF受体数量显著减少（168±2 fmol/mg蛋白对455±3）。夜间PC大鼠的肾小球受体也有减少。白天的头低位倾斜、卧床休息或头露出水面会引起利钠和利尿反应，而夜间正常卧位则不会导致这种效应。我们得出结论，夜间未观察到的利钠和利尿反应与血浆ANF水平升高和ANF受体密度降低有关。
