EXPERIMENTAL STUDIES ON THE CHEMOTHERAPEUTIC EFFECT ON RETROGRADE PROTEUS PYELONEPHRITIS IN RATS

The effect of chemotherapy on experimental pyelonephritis in rats was investigated by initiating treatment at various intervals after induction of the disease. An experimental model of pyelonephritis was produced by transurethral inoculation of Proteus mirabilis 24 hours after producing chemical cystitis by instilling 0.5ml of 0.75% acetic acid into bladder transurethrally. The bacterial inoculum was 0.5ml of heart infusion broth containing 106 cells/ml of P, mirabilis isolated from a 33-year-old woman with bilateral chronic pyelonephritis and renal stones. The animals were administered 100mg of ampicillin per kilogram of body weight intramuscularly twice daily for 7 days from 1, 3, 5, 7 and 10 days after inoculation. At 4 weeks after inoculation, urinary concentrating ability, renal histology, serum antibody titer and urinary tract stone formation were examined. The results obtained were as follows. 1) The incidence of pyelonephritis with this experimental model was 94.0%, including rats that died in the observation period. In controls not pretreated with acetic acid prior to P, mirabilis inoculation, the incidence of pyelonephritis was 71.7%. This difference was significant (p