飲水行動誘起に関与する神経機構と生理活性ペプチド

7KJ00000173786

Evidence Suggesting the Presence of Serotonergic Nerve Terminals on Catecholamine-Containing Subependymal Cells in the Preoptic Recess Organ of the Bullfrog(Rana catesbeiana)

The innervation of serotonergic nerve fibers to catecholamine (CA)-containing subependymal cells (cerebrospinal fluid-contacting neurons) was studied in the preoptic recess organ of the bullfrog brain by immunohistochemistry together with CA fluorescence histochemistry. Microspectrofluorometric analysis indicated that fluorescent subependymal cells in the preoptic recess organ contained mainly dopamine. By light microscopy, a number of serotonin (5HT)-immunoreactive fibers and terminals were distributed in subjacent neuropils of the subependymal layer. Double staining using the same section indicated that 5HT-immunoreactive punctate structures resembling axon terminals were situated around subependymal perikarya showing tyrosine hydroxylase (a marker enzyme for CA-containing neurons)-like immunoreactivity. A correlative analysis of the same specimen with fluorescence and electron microscopes revealed that CA-containing subependymal cells possessed numerous electron-dense granules (80-150 nm in diameter) within the perikaryal cytoplasm. Finally, immunoelectron microscopic examination confirmed that 5HT- positive nerve terminals were located closely adjacent to subependymal somata that contained similar granules to those of CA-containing cells. Although a typical synaptic feature has not yet been observed between the two structures, the present results strongly suggest that CA-containing subependymal cells receive input of serotonergic neurons via axo-somatic synapses.6KJ00004125954

High-salt in addition to high-fat diet may enhance inflammation and fibrosis in liver steatosis induced by oxidative stress and dyslipidemia in mice

Background: It is widely known that salt is an accelerating factor for the progression of metabolic syndrome and causes cardiovascular diseases, most likely due to its pro-oxidant properties. We hypothesized that excessive salt intake also facilitates the development of nonalcoholic steatohepatitis (NASH), which is frequently associated with metabolic syndrome.Methods: We examined the exacerbating effect of high-salt diet on high-fat diet-induced liver injury in a susceptible model to oxidative stress, apoE knockout and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) transgenic mice.Results: High-salt diet led to NASH in high-fat diet-fed LOX-1 transgenic/apoE knockout mice without affecting high-fat diet-induced dyslipidemia or hepatic triglyceride accumulation. Additionally, a high-salt and high-fat diet stimulated oxidative stress production and inflammatory reaction to a greater extent than did a high-fat diet in the liver of LOX-1 transgenic/apoE knockout mice.Conclusions: We demonstrated that high-salt diet exacerbated NASH in high-fat diet-fed LOX-1 transgenic /apoE knockout mice and that this effect was associated with the stimulation of oxidative and inflammatory processes; this is the first study to suggest the important role of excessive salt intake in the development of NASH.ArticleLIPIDS IN HEALTH AND DISEASE.14:6(2015)journal articl

Evidence Suggesting the Presence of Serotonergic Nerve Terminals on Catecholamine-Containing Subependymal Cells in the Preoptic Recess Organ of the Bullfrog(Rana catesbeiana)

The innervation of serotonergic nerve fibers to catecholamine (CA)-containing subependymal cells (cerebrospinal fluid-contacting neurons) was studied in the preoptic recess organ of the bullfrog brain by immunohistochemistry together with CA fluorescence histochemistry. Microspectrofluorometric analysis indicated that fluorescent subependymal cells in the preoptic recess organ contained mainly dopamine. By light microscopy, a number of serotonin (5HT)-immunoreactive fibers and terminals were distributed in subjacent neuropils of the subependymal layer. Double staining using the same section indicated that 5HT-immunoreactive punctate structures resembling axon terminals were situated around subependymal perikarya showing tyrosine hydroxylase (a marker enzyme for CA-containing neurons)-like immunoreactivity. A correlative analysis of the same specimen with fluorescence and electron microscopes revealed that CA-containing subependymal cells possessed numerous electron-dense granules (80-150 nm in diameter) within the perikaryal cytoplasm. Finally, immunoelectron microscopic examination confirmed that 5HT- positive nerve terminals were located closely adjacent to subependymal somata that contained similar granules to those of CA-containing cells. Although a typical synaptic feature has not yet been observed between the two structures, the present results strongly suggest that CA-containing subependymal cells receive input of serotonergic neurons via axo-somatic synapses