Estrogens influence antibody coating in experimental urinary tract infection

Female rats were infected with E. coli 0.25 by intravesical instillation. After 4 weeks, significantly higher bacterial counts (bladder puncture and renal homogenates) were found in estradiol treated rats (0.5 mg/kg/week) than in solvent controls, but the proportion of antibody-coated bacteria was significantly (P less than 0.01) lower in bladder urine and renal homogenates. There was no influence of estrogens on renal histology or ureteral width. The results are compatible with an effect of estrogens on local immune response in the urinary tract.