Data from: Oxidation of linoleic and palmitic acid in pre-hibernating and hibernating common noctule bats revealed by 13C breath testing

Mammals fuel hibernation by oxidizing saturated and unsaturated fatty
acids from triacylglycerols in adipocytes, yet the relative importance of
these two categories as an oxidative fuel may change during hibernation.
We studied the selective use of fatty acids as an oxidative fuel in
noctule bats (Nyctalus noctula). Pre-hibernating noctule bats that were
fed 13C-enriched linoleic acid (LA) showed 12 times higher tracer
oxidation rates compared to conspecifics fed 13C-enriched palmitic acid
(PA). After this experiment, we supplemented the diet of bats with the
same fatty acids on 5 subsequent days to enrich their fat depots with the
respective tracer. We then compared the excess 13C enrichment (APE) in
breath of bats for torpor and arousal events during early and late
hibernation. We observed higher APE values in breath of bats fed
13C-enriched LA than in bats fed 13C-enriched PA for both states, torpor
and arousal, and also for both periods. Thus, hibernating bats oxidized
selectively endogenous LA instead of PA, most likely because of faster
transportation rates of PUFA compared with SFA. We did not observe changes
in APE values in the breath of torpid animals between early and late
hibernation. Skin temperature of torpid animals increased by 0.7oC between
early and late hibernation in bats fed PA, whereas it decreased by -0.8oC
in bats fed LA, highlighting that endogenous LA may fulfil two functions
when available in excess: serving as an oxidative fuel and supporting cell
membrane functionality.