Woods R L
Baker Medical Research Institute, Melbourne, Australia.
Am J Physiol. 1988 Dec;255(6 Pt 1):E934-41. doi: 10.1152/ajpendo.1988.255.6.E934.
To quantify the role of the kidney in whole body metabolic clearance rate (MCR) from plasma of atrial natriuretic peptide (ANP), synthetic alpha-human ANP-(1-28) was infused at 200 ng/min to steady-state conditions in chronically instrumented one-kidney conscious dogs. Clearances were measured in dogs with a normally filtering kidney and they were also measured after the glomerular filtration rate (GFR) was reduced to close to zero by acutely inflating a cuff around the renal artery (RAC), which resulted in minimal urine production and renal blood flow reduction to 59% of the resting level. In normal dogs, MCR was 1,090 +/- 134 ml/min with renal clearance rate (RCR) contributing only 13.9%. After RAC, MCR fell to 864 +/- 151 ml/min, due in part to a fall in RCR (-41.5 +/- 12.9 ml/min), but mostly due to a fall in "rest of the body" (total renal) clearance of ANP. The reduced GFR accounted for virtually all the fall in RCR. Normal plasma ANP half-life was 59.6 +/- 7.9 s. In conclusion, MCR of ANP was very high, approaching the cardiac output, suggesting that most of ANP is cleared in one circulation through peripheral tissues. GFR contributed significantly to RCR (approximately 30%) but the contribution of the kidney to whole body MCR was small relative to rest of the body clearance of ANP.
为了量化肾脏在心房利钠肽（ANP）血浆全身代谢清除率（MCR）中的作用，将合成的α-人ANP-（1-28）以200 ng/分钟的速度输注到长期植入仪器的单肾清醒犬体内，直至达到稳态。在具有正常滤过功能肾脏的犬中测量清除率，并且在通过急性扩张围绕肾动脉（RAC）的袖带使肾小球滤过率（GFR）降至接近零后也进行测量，这导致尿量极少且肾血流量减少至静息水平的59%。在正常犬中，MCR为1090±134毫升/分钟，肾清除率（RCR）仅占13.9%。RAC后，MCR降至864±151毫升/分钟，部分原因是RCR下降（-41.5±12.9毫升/分钟），但主要是由于ANP“身体其他部位”（总肾外）清除率下降。GFR的降低几乎完全导致了RCR的下降。正常血浆ANP半衰期为59.6±7.9秒。总之，ANP的MCR非常高，接近心输出量，这表明大部分ANP通过外周组织在一次循环中被清除。GFR对RCR有显著贡献（约30%），但相对于身体其他部位对ANP的清除率而言，肾脏对全身MCR的贡献较小。
