A comparative study of the kidney in two-kidney one-clip and spontaneous hypertension rats

Objective To compare the pathological changes of the kidney in two-kidney one-clip hypertension and spontaneous hypertension rats so as to provide some experimental basis for clinical prevention and treatment of primary and secondary hypertension. Methods Conventional histopathology and elastic staining methods were used to observe the morphological changes of kidney tissues and renal arterioles from two-kidney one-clip (2K1C) and spontaneously hypertensive rats (SHR) of different weeks of age. Results The blood pressure of 2K1C rats after 4 weeks of operation reached (187±24)mmHg,which was significantly higher than that of controls (P0.01). The blood pressure was (201±21)mmHg and (204±16)mmHg in SHR16-and in 24-week-old rats,respectively,which was not significantly different from that of 2K1C rats. Glomerular fibrosis and hyalinization could be seen in 6 rats of 2K1C model (85.71%,6/7). In addition,a total of (49.14±22.78) protein casts were observed in every 10 low magnification of microscopic field of vision from each 2K1C rat. However,neither glomerular fibrosis nor protein cast was found in SHR16-week-old group and SHR24-week-old group. Thickening,separation and fracture of internal elastic membrane were detected in some small arteries of 2K1C,SHR16 and SHR24-week-old groups. There was no significant difference in arteriole media/wall ratio and inner diameter/outer diameter ratio among groups. Conclusion Lesions of kidney tissues and renal arterioles in two-kidney one-clip renal hypertensive rats were more severe than those in 16-and 24-week-old spontaneously hypertensive rats. The results suggest that hypertension-induced renal and arteriole pathological changes may differ between essential hypertension and secondary hypertension.