Renal scarring due to pyelonephritis was shown to improve in rats given vitamin A

ABSTRACT Renal scarring due to pyelonephritis was shown to improve in rats given vitamin A. Aim: We aimed to evaluate the effect of vitamin A in a renal ablation nephropathy model. Materials and Methods: Four groups each including 7 rats with 5/6 nephrectomy were formed; Group I (no vitamin A), Group II (60 klU vitamin A), Group III (120 klU vitamin A) and Group IV (180 klU vitamin A). Four sham- operated rats constructed the control group. After 6 weeks of 5/6 nephrectomy, the rats were sacrificed and serum creatinine, vitamin A and [5-carotene levels were determined in addition to histopathologic evaluation of the remnant kidneys. The tubulointerstitial and glomerular changes were graded as "0-3" and "0-5" respectively in accordance with the severity of the lesions. Tubulointerstitial score (TIS), mean glomerulosclerosis score (MGS, arithmetical mean of the sclerosis scores of 100 glomeruli) and severity of glomerulosclerosis index (SGI, ratio of the number of glomeruli with grade >3 sclerosis to the total number of glomeruli examined) were calculated for each rat. Results: Serum creatinine levels were higher in the study groups compared to the control rats (p<0.05), but there was no significant difference between the study groups, although the levels increased as the dose of vitamin A increased. Serum vitamin A levels were significantly higher in the groups given vitamin A than the control rats and Group I (p<0.05). In addition, serum vitamin A levels increased significantly in parallel to increasing doses of vitamin A (p<0.05). Serum P-carotene levels did not differ between the groups, excluding the difference between the control group and Group II being lower in the latter (p=0.01). MGS and SGI were significantly higher in the study groups compared to the control rats (p<0.05), but did not differ between the study groups. Study and control rats were not different with respect to TIS, but a difference was present between the control group and Group HI (p=0.04). Group II had the lowest MGS, SGI and TIS scores among the study groups. When all the rats were taken into consideration in combination, vitamin A levels did not correlate to the MGS and SGI, but correlated positively to the TIS (r=0.391, p=0.027). P-carotene levels also did not correlate to the MGS, SGI and TIS. 43Conclusion: Vitamin A administration did not affect significantly the clinical and pathological course of renal ablation nephropathy in rats. Furthermore, higher doses of vitamin A might even be damaging to renal tissue. 44