Ohlson M, Sörensson J, Lindström K, Blom A M, Fries E, Haraldsson B
Department of Physiology, Göteborg University, Göteborg SE-504 30, Sweden.
Am J Physiol Renal Physiol. 2001 Jul;281(1):F103-13. doi: 10.1152/ajprenal.2001.281.1.F103.
The effect of shape on the transglomerular passage of solutes has not been hitherto systematically studied. We perfused isolated rat kidneys to determine the fractional clearances (theta) at various filtration rates for four molecules of different shapes but with similar Stokes-Einstein radii (aSE = 34-36 A). The theta for hyaluronan, bikunin, and Ficoll36 A were 66, 16, and 11%, respectively, at a glomerular filtration rate (GFR) of 0.07 ml x min(-1) x g wet wt(-1) and decreased to 46, 14, and 7%, respectively, on a fivefold increase in GFR. Under the same conditions, theta for albumin increased from 0.15 to 0.74%, and similar behavior was observed for larger Ficolls (aSE >45 A). Pore analysis showed that the "apparent neutral" solute radii of Ficoll, albumin, bikunin, and hyaluronan were 35, 64, 33, and 24 A, respectively, despite similar aSE. In addition, the properties of the glomerular filter changed with increasing GFR and hydrostatic pressure. We conclude that elongated shape, irrespective of size and charge, drastically increases the transglomerular passage of a solute, an effect that is related to its frictional ratio.
形状对溶质跨肾小球滤过的影响迄今尚未得到系统研究。我们对离体大鼠肾脏进行灌注，以测定四种形状不同但斯托克斯 - 爱因斯坦半径相似（aSE = 34 - 36 Å）的分子在不同滤过率下的分数清除率（theta）。在肾小球滤过率（GFR）为0.07 ml x min⁻¹ x g湿重⁻¹时，透明质酸、比 Kunin和Ficoll36 Å的theta分别为66%、16%和11%，当GFR增加五倍时，分别降至46%、14%和7%。在相同条件下，白蛋白的theta从0.15%增加到0.74%，对于更大的Ficolls（aSE > 45 Å）也观察到类似行为。孔隙分析表明，尽管aSE相似，但Ficoll、白蛋白、比 Kunin和透明质酸的“表观中性”溶质半径分别为35 Å、64 Å、33 Å和24 Å。此外，肾小球滤过器的特性随GFR和静水压力的增加而变化。我们得出结论，无论大小和电荷如何，细长形状会显著增加溶质的跨肾小球滤过，这种效应与其摩擦比有关。
