The Role of transforming growth factor-beta in renal scarring due to experimental pyelonephritis in rats and prevention of renal scarring with antiinflammatory treatment

The role of transforming growth factor-P in renal scarring due to experimental pyelonephritis in rats and prevention of renal scarring with antiinflammatory treatment The relationship between infection, renal scarring, antiinfective and antiinflammatory therapies and inflammatory mediators of TGF- |3 and a-SMA was studied in an experimental model of pyelonephritis in rats. Pyelonephritis was produced in four to six week-old Wistar albino rats by direct inoculation of a rat nephropathogenic E. Coli type 06 K13 HI. The animals were divided into three groups with 20 rats in each: Group I received no tratment. Group II treated with antibiotic only ( cephtriaxone, 200 mg/kg, IM, one dairy dose for 5 days ) started on the 3rd day of bacterial challenge. Group in treated with antibiotic in the same manner as in Group II plus glucocorticoid ( prednisolone, 2 mg/kg, subcutaneousry, one daily dose for 5 days ) started on the 3rd day of infection. Half of the rats in each group were sacrificed at 7- 9th days ( Early stage ) and the remaining at the 31 -36th days after bacterial inoculaation ( Later stage ). The kidneys were examined according to three pathological criteria ( fibrosis, mononuclear cellular infiltration and tubular atrophy ) and two immunohistochemical parameters ( TGF- p and a -SMA ). All of the parameters were found significantly lower in treatment groups than in Group I at the early stage. There were no difference between two treatment groups. At the later stage the only significant finding was the less staining of TGF- P in Group HI than in Group II Both treatments were found effective in the acute phase, but these effects did not continue into the later stages. It is suggested that TGF- P and a -SMA may play a role in renal scarring after pyelonephritis and these cytokines may be mediators of antiinflammatory actions of corticosteroids in scar tissue reduction. Key words: Urinary tract infection, renal scarring, transforming growth factor-P, o- smooth muscle actin, antiinflammatory treatment vn