Black M Jane, Wang Yao, Bertram John F
Department of Anatomy and Cell Biology, Monash University, Clayton, Melbourne, Vic., Australia.
Kidney Blood Press Res. 2002;25(1):20-6. doi: 10.1159/000049431.
BACKGROUND/AIMS: A reduction in nephron endowment leading to reduced renal filtration surface area has been implicated in the development of hypertension. The aim of this study was to compare glomerular (and thereby nephron) number and renal filtration surface area in young Wistar-Kyoto rats (WKY) with young spontaneously hypertensive rats (SHR), prior to the development of hypertension in this model.
Using unbiased stereological methods the number and size of glomeruli, as well as total renal filtration surface area were determined in perfusion-fixed kidneys of 4-week-old WKY and SHR.
At 4 weeks of age, in weight-matched animals, there was no significant difference in the number of glomeruli in the kidneys of SHR compared to WKY (28,620 +/- 1,643 and 25,670 +/- 1,263 glomeruli/kidney, respectively). Similarly, there was no difference in mean glomerular volume (SHR: 4.70 +/- 0.31 x 10(-4) mm(3); WKY: 4.28 +/- 0.20 x 10(-4) mm(3)). Surprisingly, total renal filtration surface area was significantly greater in SHR than WKY (3,867 +/- 116 and 3,176 +/- 83 mm(2), respectively).
The renal abnormality underlying the development of hypertension in the SHR is not due to inborn deficits in nephron endowment and/or filtration surface area.
背景/目的:肾单位数量减少导致肾滤过表面积减小与高血压的发生有关。本研究的目的是在该模型出现高血压之前,比较年轻的Wistar-Kyoto大鼠(WKY)和年轻的自发性高血压大鼠(SHR)的肾小球数量(从而肾单位数量)和肾滤过表面积。
采用无偏倚的体视学方法,测定4周龄WKY和SHR灌注固定肾脏中肾小球的数量和大小,以及总肾滤过表面积。
在4周龄时,体重匹配的动物中,SHR肾脏中的肾小球数量与WKY相比无显著差异(分别为28,620±1,643个/肾和25,670±1,263个/肾)。同样,平均肾小球体积也无差异(SHR:4.70±0.31×10⁻⁴mm³;WKY:4.28±0.20×10⁻⁴mm³)。令人惊讶的是,SHR的总肾滤过表面积显著大于WKY(分别为3,867±116mm²和3,176±83mm²)。
SHR高血压发生的潜在肾脏异常并非由于肾单位数量和/或滤过表面积的先天性缺陷。