A Circadian susceptibility-resistance cycle to fluothane in male B1 mice

Abstract

The mortality of mature, male B1 mice upon exposure to 35 per cent Fluothane in oxygen for 10 minutes may be as low as 5 per cent oi as high as 76 per cent, depending upon the oiganism's circadian system phase, Predictably peiiodic changes in susceptibility can be found in test animals of several age groups, apart from differences in susceptibility as a function of age Further consideration of the organism's time structure, as revealed by its rhythms, may lead to safer anaesthetic practices. © 1964 Canadian Anesthesiologists.