[Demonstration of seasonal changes of circadian rhythms of amikacin chrononephrotoxicity in rats].

The present study investigates the chronobiological approach of the amikacin-induced nephrotoxicity in rats treated with a single sublethal dose administered at different times of day. The nephrotoxicity is appreciated by gamma-glutamyl-transferase and N-acetyl-beta-D-glucosaminidase urinary excretion, respectively a brush border and a lysosomal enzyme. These excretions peak out at 14:00 and reach a through at 20:00. In contrast, in a precedent experimentation, in october/november, we evidence gamma-glutamyl-transferase excretion increased at 20:00. So, we evidenced with amikacin not only a circadian but also a seasonal susceptibility in rats.