The role of vitamin A in preventing renal scarring secondary to pyelonephritis

Objective To evaluate the efficiency of exogenously administered vitamin A in preventing renal scarring caused by experimental pyelonephritis in rats. Materials and methods Forty Wistar rats were injected with 0.1 mL of soluti on containing Escherichia coli (10(10)/mL) into both renal medullae. Five e qual groups were then formed: group I was treated only with ciprofloxacin ( 30 mg/kg per day, twice daily, intraperitoneally) for 5 days, starting 3 da ys after bacterial inoculation; in group 2, 60 kIU of vitamin A was injecte d intramuscularly with the bacterial inoculation; in group 3, 60 KIU of vit amin A was injected similarly, but 3 days after bacterial inoculation; in g roup 4, 60 kIU of vitamin A was given orally with the bacterial inoculation ; and group 5 was treated with ciprofloxacin for 5 days and vitamin A intra muscularly from the third day after bacterial inoculation. All the rats wer e killed 6 weeks after bacterial injection; blood samples were obtained to determine serum vitamin A and p-carotene levers, and both kidneys were exam ined pathologically for scarring, graded as 0 (none), 1 (mild), 2 (moderate ) and 3 (severe). Results Serum Vitamin A levers were higher in the rats given vitamin A (gro up 2-5) than in group 1, being highest in group 4, although only this group had significantly higher levels of vitamin A than group 1 (P < 0.05). Hist opathologically, the fibrosis was mildest in groups 2 and 4 (two of 16 kidn eys grade 1), whereas it was most severe in group 1 (all 16 grade 2-3). Fib rosis was significantly less in groups 2-5 than in group 1 (P < 0.05). Ther e was a significant negative correlation between vitamin A levels and the s um of the fibrosis, inflammation and tubular atrophy scores of all rats (r = -0.391, P < 0.02). P-carotene levels were unrelated to renal scarring. Conclusion The administration of vitamin A could have a role in preventing renal scar formation from pyelonephritis induced experimentally in rats.