No abstract

No abstract

The subfornical organ is an essential central nucleus for angiotensin II-induced body fluid regulation. Similar to angiotensin II, centrally injected neurokinin B (NKB) may induce cardiovascular responses by the subfornical organ; however, it does not induce water intake. To clarify this inconsistency, we investigated the neuronal effects of NKB on subfornical organ neurons in slice preparations along with its behavioral effects in vivo. In electrophysiological extracellular recordings, NKB excited angiotensin II-insensitive and inhibited angiotensin II-sensitive neurons. Centrally injected NKB inhibited peripherally injected angiotensin II-induced water intake. These results suggest that NKB-mediated neuronal effects on the subfornical organ are likely to be involved in antidipsogenic responses in addition to the previously reported cardiovascular responses.

No abstract

We have demonstrated that microsomal prostaglandin E synthase-1 (mPGES-1), an inducible terminal enzyme for PGE 2 synthesis, is a critical factor of stroke-reperfusion injury. In this study, we investigated the role of mPGES-1 in neuroinflammation and neurological dysfunctions observed after intracerebral hemorrhage (ICH). Collagenase was injected into the left striatum of adult mPGES-1 knockout (KO) and wild-type (WT) mice. In WT mice, mRNA and protein of mPGES-1 were significantly up-regulated in striatum and cerebral cortex after ICH. In mPGES-1 KO mice, although the hemorrhage and edema size were almost the same as WT mice, survival rate was significantly higher than WT mice. The PGE 2 production, TNF-α induction and glial activation after ICH in mPGES-1 KO brain were significantly less than those in WT brain. DAPI and TUNEL staining showed ICH-induced nuclear condensation and DNA fragmentation in mPGES-1 KO striatum were less than those in WT striatum. Furthermore, mPGES-1 KO mice showed better performance in stepping error test, rotarod test and neurological dysfunction scoring compared with the WT mice. These results suggest that mPGES-1 contributes to ICH-induced neuroinflammation, neuronal apoptosis, neurological dysfunctions and mortality through PGE 2 production. Thus, mPGES-1 may be a new therapeutic target for ICH.