Protective effect of N-acyl amino acids (NAAs) on cephaloridine (CER) nephrotoxicity in rabbits

The protective effect of N-acyl amino acids (NAAs) against cephaloridine (CER)-induced nephrotoxicity was studied in rabbits. A large single intravenous dose of CER (more than 100 mg/kg) induced severe proximal tubular necrosis. Simultaneous treatment with several NAAs (at dosages of 100, 200 mg/kg, etc., i.v.), such as N-benzoyl-beta-alanine (NBBA), N-benzoyl-6-aminocaproic acid, and N alpha,epsilon-dibenzoyl-D,L-lysine, remarkably suppressed the histopathological damage in the kidney induced by CER. NAAs have generally low toxicity in laboratory animals (e.g., the LD50 of NBBA was more than 3,000 mg/kg, i.v. in rats), and NAAs were suggested to be good candidates for reducing the nephrotoxicity of CER and other beta-lactam antibiotics.