Glycerol-3-phosphate oxidation in brown adipose tissue mitochondria of cold-adapted hamster is strongly inhibited by phospholipase A2 (PLA2)- Our data show that the glycerol-3-phosphate branch of the respiratory chain is sensitive to PLA2 action more than the succinate branch and that the transfer of reducing equivalents from the glycerol-3-phosphate dehydrogenase to arteficial electron acceptor is especially sensitive to the PLA2 action.