Central efferent control of nonshivering thermogenesis in rats

摘要

Removal of the midbrain tonic inhibitory mechanism (MTIM) on nonshivering thermogenesis (NST) increases temperatures of the interscapular brown adipose tissue (T-IBAT) and rectum (T-rec) in Urethane-anesthetized rats through disinhibition-induced activation of the central sympathetic nervous system. The magnitude of T-IBAT and T-rec increases by midbrain procaine microinjections during hypothalamic warming and cooling was smaller and larger, respectively, than that during thermoneutral hypothalamic temperature. In conscious animals, the midbrain procaine administration increased body temperature more in decerebrated than in control animals. It was concluded that the hypothalamus exerts its modulatory influences on the MTIM. However, its mode of action is not known.