It has been proposed that serotonin (5-HT) facilitates the chemosensory activity of the carotid body (CB). In the present study, we investigated mRNA expression and immunohistochemical localization of the 5-HT synthetic enzyme isoforms, tryptophan hydroxylase 1 (TPH1) and TPH2, and the 5-HT plasma membrane transport protein, 5-HT transporter (SERT), in the CB of the rat. RT-PCR analysis detected the expression of mRNA for TPH1 and SERT in extracts of the CB.
View Article and Find Full Text PDFUnder long-term hypoxia, noradrenaline (NA) content in the carotid body (CB) increases, suggesting that NA plays an important role in CB chemotransduction. However, it is unknown whether short-term hypoxia upregulates NA biosynthesis in CB. Therefore, we examined dopamine β-hydroxylase (DBH) expression in the CB of rats exposed to hypoxia (10% O(2)) for 0 to 24 hr with immunoblotting and immunohistochemistry.
View Article and Find Full Text PDFMorphological development of sensory structures in the laryngeal mucosa of postnatal rats was observed by use of immunohistochemistry for protein gene-product 9.5 (PGP9.5).
View Article and Find Full Text PDFNitric oxide (NO) is a free radical and produced from L-arginine by nitric oxide synthase (NOS). Since NO is recently suggested to be involved in olfactory perception, the expression of eNOS, an isoform of NOS, was examined in the rat olfactory epithelium. The activity of NADPH-diaphorase was also examined as a marker of NOS.
View Article and Find Full Text PDFIn the carotid body (CB), it has been reported that the expressions of tyrosine hydroxylase (TH) mRNA and TH protein are enhanced by exposure to hypoxia. However, it is not known whether CO(2) affects the expression of TH in the CB. We examined the expression of TH mRNA and the immunoreactivity for TH in the CB of rats exposed to hypoxia (10% O(2)), hypercapnia (10% CO(2)) and hypercapnic hypoxia (10% O(2) and 10% CO(2)) for 2-24 h.
View Article and Find Full Text PDFJ Histochem Cytochem
September 2010
Neurochemical and morphological changes in the carotid body are induced by chronic hypoxia, leading to regulation of ventilation. In this study, we examined the time courses of changes in immunohistochemical intensity for tyrosine hydroxylase (TH) and cellular volume of glomus cells in rats exposed to hypoxia (10% O(2)) for up to 24 hr. Grayscale intensity for TH immunofluorescence was significantly increased in rats exposed to hypoxia for 12, 18, and 24 hr compared with control rats (p<0.
View Article and Find Full Text PDFIn the sensory ganglia, neurons are devoid of synaptic contacts, and ganglion neurons surrounded by one of glial cells, satellite cells. Recent studies suggest that neurons and satellite cells interact through neurotransmitters. In the present study, intracellular Ca(2+) ([Ca(2+)](i)) dynamics of neurons and satellite cells from one of viscerosensory ganglia, nodose ganglion (NG), were investigated by stimulation with glutamate and its agonist and/or the antagonist of the GABA(A) receptor bicuculline.
View Article and Find Full Text PDFICR-derived glomerulonephritis (ICGN) mice are a known inbred strain with hereditary nephrotic syndrome and are considered a good animal model of human idiopathic nephrotic syndrome. ICGN mice show proteinuria at a young age, and hypoalbuminemia, hyperlipidemia, anemia and edema accompanies their symptoms with aging. In addition, ICGN mice develop severe anemia with the progression of renal fibrosis similar to human chronic kidney disease (CKD).
View Article and Find Full Text PDFThere are two functional pathways for the nasotrigeminal reflex: the spinal nucleus of trigeminal nerve (SPV) to the Kölliker-Fuse (KF) nucleus and the nucleus of solitary tract (NTS) to the lateral parabrachial nucleus (PBl). Although stimulation of the nasal mucosa by cool temperature induces respiratory depression, it is still unknown whether these nuclei are activated. In the present study, we examined the expression of Fos protein in rat brainstem neurons after nasal application of l-menthol, which is known to activate cold-sensitive nasal receptors.
View Article and Find Full Text PDFThe ICR-derived glomerulonephritis (ICGN) mouse is an appropriate model for anemia associated with chronic renal disorder (CRD). Insufficient renal production of erythropoietin (EPO) induces the anemia associated with CRD. EPO mRNA is expressed in both kidneys and liver of progressing-stage ICGN mice.
View Article and Find Full Text PDFAnemia is a major secondary symptom in chronic renal disorder (CRD), but the precise cause of insufficient production of erythropoietin (EPO) remains unclear owing to the controversial localization of EPO-producing cells in the kidneys. The ICR-derived glomerulonephritis (ICGN) mouse, a new hereditary nephrotic mouse, is an appropriate model of anemia associated with CRD. By using an amplified in situ hybridization technique, we detected and counted the renal EPO-producing cells under both normoxic and hypoxic conditions.
View Article and Find Full Text PDFICR-derived glomerulonephritis (ICGN) mice are a novel inbred strain with hereditary nephrotic syndrome and are thus considered a good animal model of human idiopathic nephrotic syndrome. In the present study, we investigated the effect to erythrocyte production by human erythropoietin (hEPO) treatment in ICGN mice during the early nephrotic stage. Erythrocyte count, hemoglobin concentration and hematocrit value in hEPO-treated (5 U/body/day, for 5 days) ICGN mice were recovered to the levels found in normal ICR mice.
View Article and Find Full Text PDFThe ICR-derived glomerulonephritis (ICGN) mouse, a novel inbred mouse strain with a hereditary nephrotic syndrome, develops severe anemia associated with chronic renal failure. To reveal the pathogenic mechanism of anemia in ICGN mice, we subcutaneously administered recombinant human erythropoietin (rhEPO; 5 IU/mouse/day) or saline for 5 days to ICGN mice. In terminal-stage ICGN mice with severe anemia, rhEPO significantly increased hematocrit (Ht), red blood cells (RBC) and hemoglobin levels.
View Article and Find Full Text PDFThe ICR-derived glomerulonephritis (ICGN) mouse, a new inbred mouse strain with a hereditary nephrotic syndrome, is considered to be a good model of human idiopathic nephrotic syndrome and notably exhibits proteinuria and hypoproteinemia from the neonatal stage. In chronic renal disorder (CRD), anemia is a major subsequent symptom (renal anemia). The precise cause of renal anemia remains unclear, primarily owing to the lack of appropriate spontaneous animal models for CRD.
View Article and Find Full Text PDFRenal fibrotic change, extreme accumulation of extracellular matrix (ECM) components in glomeruli and tubulointerstitum, is one of the characteristic features of ICR-derived glomerulonephritis (ICGN) mice. Decreased degradation of ECMs by matrixmetalloproteinases was demonstrated in kidneys of ICGN mice. To determine the balance between production and degradation of ECMs in kidneys of ICGN mice, we examined expression of mRNAs of ECMs in those.
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