COLD RESISTANCE OF THE BRAIN DURING HIBERNATION: THE ROLE OF STEARYL CoA DESATURASE IN BRAIN AND LIVER AS THE SOURCE FOR MONOENES

— Brain and liver stearyl CoA desaturase activity and its associated microsomal electron transport chain was investigated in both the warm‐adapted and hibernating hamster. It was shown that the activity of this enzyme in brain was essentially the same in both the warm‐adapted and hibernating hamster. In liver an 8‐fold increase in desaturase activity was observed for the hibernator without corresponding increases in the activity of the microsomal electron transport chain. It is concluded that the increase of monoenes in brain that contributes to the lipid adaptation probably results from peripheral production of these fatty acids.