抄録
We already demonstrated that the splenic NK cell cytotoxicity (NK activity) was reduced by restraint water immersion stress through nervous and humoral mechanism. In this study we investigated the central origin of nervous mechanism. We chose hypothalamic paraventricular nucleus (PVN) in which c-fos protein was revealed by restrained water immersion stress. This result means that PVN was activated by water immersion stress. The NK activity was measured by release of chromium51 from YAK-1 cells. PVM lesion was made by passing anodal current (0.1 or 0.05mA, for 30sec) through a monopoler electrode. The localization of lesion site was confirmed by cryostat sections. PVN lesion by 0.1mA of anodal current enhanced NK activity with statistical significance. PVN lesion by 0.05mA showed the tendency of enhancement in NK activity but did not have statistical significance. The lesion of hypothalamic ventromedial nucleus (VMH) by 0.1mA and lateral hypothalamus (LH) by 0.05mA reduced NK activity. These results suggested that restraint water immersion stress might reduce NK activity through PVN. On the other hand, these results indicated the possibility that VMH and LH might enhance NK activity in tonic manner. [Jpn J Physiol 55 Suppl:S235 (2005)]
