Riegel J A
J Exp Biol. 1978 Apr;73:261-77. doi: 10.1242/jeb.73.1.261.
Single glomerulus filtration rate in Eptatretus stouti averaged 20.3+/-2.13 (S.E.M.) nl min(-1). Single glomerulus glomerular filtration rate (GFR) could be correlated with arterial pressure when arterial pressure exceeded about 4 cm H2O. Glomerular filtration was affected by postglomerular resistance brought about by alteration of the volume of urinary spaces. Filtration undoubtedly plays a role in glomerulus function. However, average colloid osmotic pressure (COP) of the plasma is almost double the average hydrostatic pressure in the segmental arteries serving the glomeruli. The COP of glomerular fluid is essentially nil, therefore it is difficult to see how pressure filtration alone can account for primary urine formation. When single glomeruli were perfused with colloid-containing Ringer at pressures within the normal range of blood pressures, GFR was within the normal range. GFR was related inversely to the colloid osmotic pressure of the perfusion Ringer. Colloid entered the urine during perfusion. However, in only a few instances did this result in conditions favourable to pressure filtration. To assess the role of active processes in glomerular filtration, chemical inhibitors were added to the perfusion Ringer. Amiloride, acetazolamide, cyanide, 2-deoxy-D-glucose, iodoacetate and ethacrynic acid were without marked effect on glomerular filtration. Ouabain and dinitrophenol markedly reduced GFR; inhibition was probably not due to indirect effects upon the renal vasculature.
stouti七鳃鳗的单个肾小球滤过率平均为20.3±2.13（标准误）nl min⁻¹。当动脉压超过约4 cm H₂O时，单个肾小球的肾小球滤过率（GFR）与动脉压相关。肾小球滤过受尿腔容积改变所引起的球后阻力影响。滤过无疑在肾小球功能中起作用。然而，血浆的平均胶体渗透压（COP）几乎是为肾小球供血的节段动脉平均静水压的两倍。肾小球液的COP基本为零，因此很难看出仅靠压力滤过如何能解释原尿的形成。当在正常血压范围内的压力下用含胶体的林格液灌注单个肾小球时，GFR在正常范围内。GFR与灌注林格液的胶体渗透压呈负相关。灌注期间胶体进入尿液。然而，只有少数情况下这会导致有利于压力滤过的条件。为了评估主动过程在肾小球滤过中的作用，向灌注林格液中添加了化学抑制剂。氨氯吡咪、乙酰唑胺、氰化物、2-脱氧-D-葡萄糖、碘乙酸和依他尼酸对肾小球滤过无明显影响。哇巴因和二硝基苯酚显著降低GFR；抑制作用可能不是由于对肾血管系统的间接影响。
