1-n-methyl-5-thiotetrazole and Body-Weight

N-Methyltetrazolethiol (NMTT) and NMTT-containing cephalosporin antibiotics cause characteristic testicular lesions in young but not adult rats. In addition, NMTT-containing cephalosporins inhibit aldehyde dehydrogenase and have been associated with a disulfiram-like reaction in humans and animals. Therefore, the potential testicular toxicity of disulfiram (10, 30, or 100 mg/kg) was evaluated in 37-day-old rats given oral doses on Postpartum Days 6 through 36, and was compared to the toxicity induced by NMTT (100 mg/kg). NMTT and each dose of disulfiram caused a decrease in testes weight. By DNA flow cytometry, testicular cell suspensions from rats given 100 mg/kg of NMTT had a 40% reduction in spermatids while those from rats given 10, 30, or 100 mg/kg of disulfiram had reductions of 52, 61, or 89%, respectively. Microscopically, the testes of rats given either NMTT or disulfiram had qualitatively similar changes, characterized by delayed maturity of the leading waves of germinal cells which had reached early maturation phase in control animals. Moderate to severe reduction occurred in the total number of spermatids with complete absence of acrosome phase and maturation phase spermatids. There was also a prominent reduction in the number of spermatocytes. Reduction in number of spermatogonia was minimal. While the mechanism of toxicity is not known for either compound, it is possible that the toxicity was related to the enzyme-inhibitory effects which both compounds possess. By defining the mechanism of testicular toxicity for compounds which cause a NMTT-like testicular toxicity in rats, biological differences in the spermatogenic process between the young and adult rat may be further understood. Direct extrapolation of the testicular effects in neonatal rats to man is not possible because of the substantial differences in initiation of spermatogenesis between rodents and humans.

Topics: Aldehyde Dehydrogenase; Animals; Animals, Newborn; Body Weight; Disulfiram; Flow Cytometry; Male; Organ Size; Rats; Spermatogenesis; Testis; Tetrazoles

The effects of cefmetazole (CMZ), a cephem antibiotic which contains the N-methyltetrazolethiol (NMTT) side-chain moiety, were compared in infant (6-42 days of age) and pubertal (6-10 weeks of age) male Sprague-Dawley rats. High doses of either CMZ or free NMTT caused reductions in testicular weight and delayed maturation of spermatogenic germ cells in the testes of infant rats, implicating NMTT as the active component in causing these effects. Pubertal rats expressed neither of these effects, even when treated with doses of CMZ far in excess of those used in infant rats. The effects of CMZ and NMTT on testicular weights and histologic features of testes of rats treated as infants were mainly reversed when these animals were examined 35 and 70 days after cessation of treatment. All reproductive functional parameters were normal in mating studies using male rats which had been treated with CMZ or NMTT as infants and allowed to recover. Because of the species differences in rates of sexual maturation and the greater rate at which rats metabolize CMZ to NMTT, the relevance to humans of the testicular effects of CMZ in infant rats is unknown.

Topics: Animals; Animals, Newborn; Azoles; Body Weight; Cefmetazole; Female; Genitalia, Male; Male; Organ Size; Rats; Seminiferous Tubules; Spermatids; Spermatogenesis; Testis; Tetrazoles; Time Factors

Antibiotic therapy, using penicillins or cephalosporins, is frequently required in patients on maintenance hemodialysis. Points to consider are dose adjustment for drugs which are excreted via the kidney, drug dialysability, and cumulation with frequent occurrence of side reactions, neurotoxicity and bleeding being the clinically most important ones. For third-generation cephalosporins with N-methylthiotetrazole side chain, impaired intrahepatic vitamin K metabolism may cause problems of hemostasis which can be avoided by dose adjustment and prophylactic administration of vitamin K1.

Topics: Bacterial Infections; Body Weight; Cephalosporins; Dose-Response Relationship, Drug; Drug Administration Schedule; Hemorrhage; Humans; Kidney Failure, Chronic; Kinetics; Penicillin Resistance; Penicillins; Renal Dialysis; Tetrazoles; Vitamin K 1