腎表層容積脈波に関する研究 ： 腎動脈狭窄および瀉血時の体循環，腎循環の変化との関係

Abstract

In order to investigate the changes in systemic and renal hemodynamics induced by renal arterial constriction and venesection, arterial blood pressure (ABP), cardiac output (CO), renal blood pressure (RBP), renal blood flow (RBF), creatinine clearance (Ccr), PAH clearance (C＿＜PAH＞) and renal plethysmogram (RPTG) were simultaneously determined in dogs. RPTG was recorded with a fiberoptic photoelectric plethysmograph, a device directly detecting intervascular volume changes from organ surfaces. By renal arterial constriction, ABP and RBP increased slightly, and CO decreased slightly. Both total systemic peripheral resistance (TPR) and renal vascular resistance (RVR) increased, although the magnitude of the increase varied according to the grade of stenosis. As for changes in pulse waves, time intervals from the ECG Q wave to the upstroke (S) point was gradually prolonged in the order of ABP, RBP and RPTG. That is, the more peripheral the site of measurement was, the more prolonged the time interval was. Time intervals from S-point to the peak (P) of RPTG tended to be shortened by constriction, while those of ABP and RBP did not change significantly. The dicrotic index (Hn/Hp) of RBP and RPTG was reduced as the renal blood flow decreased, although Hn/Hp of ABP did not exhibit any change. By venesection, both blood preasure (ABP and RBP) and blood flow (CO and RBF) decreased, although the magnitude of the decrease was slight in renal circulation (RBP and RBF). TPR was increased during bleeding, while RVR was unchanged. As for pulse wave changes, the QS period was significantly prolonged in ABP, RBP and RPTG. The SP period was shortened in ABP, RBP and RPTG. Hn/Hp increased in ABP, RBP and RPTG. From these results, it is concluded that we can pre-estimate the changes in renal hemodynamics caused by renal arterial constriction and venesection through RPTG. Particularly, when renal perfusion pressure is maintained up to about 25%, it seems to provide useful information.