Role of Renal Nerves in the Hypotensive and the Renal Effects of Atrial Natriuretic Factor in Rats

大白鼠腎神經在心房利鈉素產生之降血壓和腎臟作用中的角色

高美媚(Mei-Mei Kau) ； 吳劍男(Jian-Nan Wu) ； 黃萬出(Wann-Chu Huang)

《The Chinese Journal of Physiology》 33卷1期 (1990/03) Pp. 5-18

摘要

我們己往的實驗顯示心房利鈉素具降血壓、利尿和利鈉排泄的作用，而腎神經活性的改變亦會影響排泄功能。以前少數的研究則認為心房利鈉素會改變腎神經的活性。因此，本實驗旨在探討腎神經在心房利鈉素之利尿與利鈉排泄作用中的角色。實驗以麻醉大白鼠為對象，區分為四組：包括對照組、急性切除單側腎神經並灌注心房利鈉素或生理鹽水兩小組及慢性切除腎神經組。實驗時由靜脈灌注 0.15，0.30和0.45μg/kg•min三種劑量之心房利鈉素並觀測動脈壓和腎功能反應。在正常鼠，灌注心房利鈉素引起血壓下降，其幅度視劑量而異。腎小球濾過率未呈顯著性改變，但兩側腎臟的尿流量、鈉和鉀之總排泄率和排泄分率皆顯著地增高。切除單側腎神經後之血壓及腎小球濾過率皆未改變，但使該側腎臟產生利尿和利鈉排泄反應，而對側腎排泄功能未呈顯著的改變。其後接著灌注心房利鈉素使血壓下降，唯未改變腎小球瀘過率，但兩側腎臟的尿流量和鈉與鉀之排泄率皆顯著地增加。在慢性切除腎神經鼠灌注心房利鈉素也使血壓下降及腎排泄水分和鈉均增多。這些結果顯示心房利鈉素之產生利尿和利鈉排泄作用並非肇因於腎神經活性降低所致，且腎神經存在與否無關心房利鈉素的降血壓及腎臟之作用。

並列摘要

Our earlier studies have demonstrated that atrial natriuretic factor (ANF) can produce hypotensive, natriuretic and diuretic effects and that changes in the renal nerve activity can alter the renal excretory function. A few previous studies suggested that ANF could change the renal nerve activity. Thus, the present study was designed to assess the role of the renal nerve in the natriuretic and diuretic effect of ANF. Experiments were conducted on four groups of anesthetized Sprague-Dawley rats: normal control rats, unilateral acute renal denervated rats with and without ANF administration and chronic renal denervated rats. The arterial blood pressure and the renal function responses to intravenous infusion of graded doses of ANF (atriopeptin III. 0.15, 0.30 and 0.45μ/kg.min) were studied. In normal rats, infusion of ANF significantly decreased the mean arterial blood pressure in a dose-related pattern (from 109±2 to 107±3, 102±4 and 89±5 mmHg, respectively). The glomerular filtration rate (GFR) did not change significantly whereas the urine flow and the absolute and the fractional excretion rates of sodium and potassium were significantly increased. Renal denervation alone did not change the blood pressure and GFR, but produced ipsilateral diuresis and saluresis without changing the function of the contralateral kidney. Subsequent administration of ANF decreased the blood pressure but did not affect bilateral GFR. There were significant increments in the urine flow and the excretions of sodium and potassium in both the denervated and the contralateral kidneys. Infusion of ANF into chronic renal denervated rats also reduced the blood pressure and increased the renal excretion of water and sodium. These results indicate that the diuretic and the natriuretic effects of ANF is not resulted from a decreased activity of the renal efferent nerve and that the hypotensive and the renal effects of ANF are independent of renal innervation.

並列關鍵字

atrial natriuretic factor ； renal denervation ； diuresis ； natriuresis ； GFR