Woods L L
Division of Nephrology and Hypertension, Oregon Health Sciences University, Portland 97201-3098.
Am J Physiol. 1993 Mar;264(3 Pt 2):R601-9. doi: 10.1152/ajpregu.1993.264.3.R601.
These studies were designed to determine the importance of the renin-angiotensin system (RAS) in the renal hemodynamic response to acute protein feeding. In chronically instrumented conscious dogs on a normal (80 meq/day) sodium intake, a 10 g/kg meal of raw beef caused glomerular filtration rate (GFR) to increase from 68 +/- 6 to 86 +/- 6 ml/min and effective renal plasma flow (ERPF) to increase from 211 +/- 14 to 263 +/- 15 ml/min. Plasma renin activity (PRA) was 0.44 +/- 0.14 ng ANG I.ml-1 x h-1 and did not change significantly. When the protocol was repeated during infusion of captopril, GFR increased from 67 +/- 11 to 97 +/- 10 ml/min, and ERPF rose from 264 +/- 74 to 392 +/- 82 ml/min after the meat meal. The dogs were then placed on a low-salt diet (approximately 7 meq/day) to physiologically activate the RAS. In sodium-restricted dogs, GFR increased from 71 +/- 7 to 104 +/- 10 ml/min and ERPF increased from 226 +/- 15 to 299 +/- 21 ml/min after the meat meal. PRA was 3.1 +/- 1.0 ng ANG I.ml-1 x h-1 and did not change. Thus neither blockade of the RAS with captopril nor activation of the RAS by salt restriction reduced the renal hemodynamic response to a meat meal. These data indicate that the RAS is relatively unimportant in the renal hemodynamic response to acute protein feeding.
这些研究旨在确定肾素-血管紧张素系统（RAS）在急性蛋白质摄入后肾脏血流动力学反应中的重要性。在钠摄入量正常（80毫当量/天）的长期植入监测装置的清醒犬中，给予10克/千克的生牛肉餐，导致肾小球滤过率（GFR）从68±6毫升/分钟增加到86±6毫升/分钟，有效肾血浆流量（ERPF）从211±14毫升/分钟增加到263±15毫升/分钟。血浆肾素活性（PRA）为0.44±0.14纳克血管紧张素I·毫升⁻¹·小时⁻¹，且无显著变化。当在卡托普利输注期间重复该方案时，肉餐后GFR从67±11毫升/分钟增加到97±10毫升/分钟，ERPF从264±74毫升/分钟增加到392±82毫升/分钟。然后将这些犬置于低盐饮食（约7毫当量/天）以生理性激活RAS。在限钠犬中，肉餐后GFR从71±7毫升/分钟增加到104±10毫升/分钟，ERPF从226±15毫升/分钟增加到299±21毫升/分钟。PRA为3.1±1.0纳克血管紧张素I·毫升⁻¹·小时⁻¹，且无变化。因此，无论是用卡托普利阻断RAS还是通过限盐激活RAS，均未降低对肉餐的肾脏血流动力学反应。这些数据表明，RAS在急性蛋白质摄入后的肾脏血流动力学反应中相对不重要。
