中枢内食塩負荷時の内因性バゾプレッシンによって腎臓交感神経活動は抑制され、これは視床下部室傍核小細胞領域のFLI抑制に一致する

抄録

There is direct evidence for dendritic vasopressin (AVP) release, which is regulated independently of secretion into the peripheral circulation, in the hypothalamus. Dendritically released AVP seems to act on AVP neurons to modulate its activity with an action of inhibitory or stimulatory. We showed how central AVP system has an effect on the neuronal activity in the paraventricular nucleus of the hypothalamus (PVN) after central salt loading pretreated with i.c.v. AVP V₁ receptor antagonist, OPC-21268 (250 μg/kg, Otsuka Pharmaceutical). The neuronal activity evaluated by Fos-like immunoreactivity (FLI) seemed to be suppressed in the PVN, especially in the parvocellular parts. Then, we make a hypothesis that the results of FLI in the parvocellular neurons might relate to the autonomic outflows. To settle this hypothesis, we recorded renal sympathetic nerve activity (RSNA) after central salt loading. The suppression of RSNA was attenuated significantly by pretreatment with i.c.v. OPC-21268. These results suggest that the suppression of RSNA after central salt loading ascribe to the decrease of neuronal activity in the parvocellular PVN via the inhibitory action of the central AVP system. [J Physiol Sci. 2008;58 Suppl:S156]