Sucrose-diet feeding induces gene expression of heat shock protein in rat brain under stress

Stress-induced hyperphagia is enhanced in the presence of sweets, particularly sucrose, which may act to attenuate stress. Recently, it was also reported that heat shock protein (HSP) may be involved in the defense against stress. To explore whether sucrose alters gene expression of HSP under stress, we determined the HSP mRNA levels in the hypothalamus, cerebellum, and cerebral cortex after restraint stress in sucrose-diet-fed rats. Competitive RT-PCR revealed that gene expressions of HSP27 in the cerebral cortex and cerebellum and of HSP70 in the cerebral cortex, hypothalamus, and cerebellum were induced by restraint stress under a sucrose-diet-fed condition. However, restraint stress by itself or sucrose diet alone did not induce expression of HSP27 or HSP70 mRNA in any of the three anatomical parts. It is suggested that sucrose facilitates the gene expression of HSP27 and HSP70 in brain after restraint stress, which may attenuate stress.