Miller P L, Meyer T W
Department of Medicine, Stanford University, Palo Alto, California.
Lab Invest. 1990 Dec;63(6):862-6.
The effect of tissue preparation on glomerular volume in normal rats was assessed. In group 1 rats (N = 8), kidney tissue was obtained by immersion-fixation of needle biopsy cores and excised slices from the left kidney and by perfusion-fixation of the remaining right kidney at close to ambient arterial pressure. In group 2 rats (N = 8), tissue was obtained by kidney perfusion at a supernormal pressure (approximately 165 mm Hg). Studies in group 1 showed that mean glomerular volume (VG) was not different in biopsy cores (1.07 +/- 0.13 x 10(6) mu 3) and in kidney slices fixed by immersion (0.92 +/- 0.09 x 10(6) mu 3). A significantly higher value for VG (1.51 +/- 0.18 x 10(6) mu 3) was obtained in kidneys perfusion-fixed at close to ambient arterial pressure. Morphometric studies showed that reduced VG in immersion-fixed tissue was associated with lowered values for peripheral capillary wall surface area (225 +/- 21 x 10(3) mu 2 versus 159 +/- 27 x 10(3) mu 2, p less than 0.05) and reduced mean capillary radius (4.5 +/- 6 mu versus 2.7 +/- 3 mu, p less than 0.05) compared with perfusion-fixed tissue. The data suggest that glomerular capillaries contract when tissue is immersion-fixed and shows that values for mean peripheral capillary wall surface area/glomerulus and mean glomerular capillary radius obtained in immersion- and perfusion-fixed tissue cannot be directly compared. Studies in group 2 showed that VG was not altered by perfusion at a supernormal pressure (1.40 +/- 0.16 x 10(6) mu 3) as compared with perfusion at ambient pressure (1.51 +/- 0.18 x 10(6) mu 3). Further studies in group 1, however, showed that values for VG obtained in paraffin-embedded tissue were approximately 40% lower than values for VG obtained in methacrylate-embedded tissue from the same kidneys.
评估了组织制备对正常大鼠肾小球体积的影响。在第1组大鼠（N = 8）中，通过对左肾穿刺活检芯和切除切片进行浸入固定，并对剩余右肾在接近体循环动脉压下进行灌注固定来获取肾组织。在第2组大鼠（N = 8）中，通过在超正常压力（约165 mmHg）下进行肾脏灌注来获取组织。第1组的研究表明，活检芯（1.07±0.13×10⁶μm³）和浸入固定的肾切片（0.92±0.09×10⁶μm³）中的平均肾小球体积（VG）没有差异。在接近体循环动脉压下进行灌注固定的肾脏中，VG值显著更高（1.51±0.18×10⁶μm³）。形态计量学研究表明，与灌注固定组织相比，浸入固定组织中VG降低与外周毛细血管壁表面积降低（225±21×10³μm²对159±27×10³μm²，p<0.05）和平均毛细血管半径减小（4.5±6μm对2.7±3μm，p<0.05）有关。数据表明，组织浸入固定时肾小球毛细血管会收缩，并且表明浸入固定和灌注固定组织中获得的平均外周毛细血管壁表面积/肾小球值和平均肾小球毛细血管半径值不能直接比较。第2组的研究表明，与常压灌注（1.51±0.18×10⁶μm³）相比，超正常压力灌注（（1.40±0.16×10⁶μm³）不会改变VG。然而，第1组的进一步研究表明，石蜡包埋组织中获得的VG值比同一肾脏甲基丙烯酸酯包埋组织中获得的VG值低约40%。
