The effect of chloramphenicol on hepatic biotransformation enzyme activity and on the duration of pentobarbital or ketamine/xylazine anesthesia in guinea pigs (Cavia porcellus).

The effect was investigated of chloramphenicol on the activities of hepatic biotransformation enzymes: aniline hydroxylase (Ah) and ethylmorphine N-demethylase (EtND), as well as on the levels of serum alanine aminotransferase (ALT) and glutamate dehydrogenase (GLDH) in guinea pigs (Cavia porcellus). Moreover, the infl uence was established of the pre-medication with chloramphenicol on the duration of anesthesia using pentobarbital and ketamine/xylazine guinea pigs. Male guinea pigs, weighing 269-353 g, were subcutaneously (s.c.) treated with 60and 100 mg chloramphenicol sodium succinate/kg body mass once a day for three days. Thereafter the anesthetics were injected: 30 mg pentobarbital/kg b.m., i.p. in one group and 60 mg ketamine/kg b.m., s.c. + 4 mg xylazine/kg b.m., s.c. in the other group. Treatment with chloramphenicol did not signifi cantly affect the concentration of serum ALT or GLDH. As expected, 100 mg chloramphenicol/kg b.m. signifi cantly decreased the activity of Ah and EtND for -36.1% and -38.6%, respectively. On the other hand, the duration of pentobarbital anaesthesia and ketamine/xylazine-induced anaesthesia in chloramphenicol pre-treated animals was not signifi cantly prolonged. Our results also indicate that decreased enzyme activity in the presence of chloramphenicol did not infl uence the hepatic metabolism of two tested anaesthetics in guinea pigs, and in contrast to dogs, cats, rats and mice, did not prolong the duration of anaesthesia.