부산대학교 도서관

Mechanism of renal excretion of ceftriaxone (CTRX, Ro 13-9904), a new beta-lactam antibiotic, was investigated in dogs and rabbits using stop-flow analysis.Both dogs and rabbits were cannulated into the ureter for collection of urine, into the vein for constant infusion of CTRX, inulin and p-aminohippuric acid, and into the artery for blood sampling. The pelvic urine was collected in fractions and the phases of distal tubular excretion (and reabsorption), proximal tubular excretion and glomerular filtration were ascertained by monitoring concentration of Na+/K+ ions, p-aminohippuric acid and inulin in each fraction. The concentration of creatinine was monitored as a parameter of urine concentration.In dogs, no specific peak of CTRX was recognized in the phase of PAH excretion nor in the entire phase of Na+/K+ reabsorption. After administration of probenecid (30 mg/kg), the peak of PAH was disappeared while the stop-flow pattern of CTRX remained virtually unchanged. These findings suggested that the renal excretion of CTRX took place mainly through glomerular filtration in this species. In rabbits, however, a specific peak of CTRX was not recognized in the phase of Na+/K+ reabsorption but in the phase of PAH excretion, indicating involvement of proximal tubular excretion of CTRX in addition to glomerular filtration.