Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mineralocorticoids (MC) play an important role in development of salt appetite. Part of this effect involves the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei, in which MC treatment increases arginine vasopressin (AVP) synthesis and release. Since the AVP system is also modulated by nitric oxide (NO), we studied if deoxycorticosterone acetate (DOCA) treatment changed the number of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) active neurons and neuronal NO synthase (nNOS)-immunoreactive (IR) cells in the PVN and SON. After four injections of DOCA (10 mg/rat per day), rats developed a salt appetite and increased NADPH-d active and nNOS-IR neurons in both nuclei. A single DOCA injection did not change salt consumption or nNOS-IR cells, but increased the number of NADPH-d positive neurons in the PVN only. Therefore, while acute MC treatment stimulated the activity of pre-existing enzyme, chronic steroid treatment recruited additional neurons showing nNOS immunoreactivity/NADPH-d activity. These data suggest a role for NO produced in the PVN and SON in DOCA stimulatory effects on AVP mRNA and salt appetite.
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PMID:Deoxycorticosterone stimulates the activity of nicotinamide adenine dinucleotide phosphate-diaphorase/nitric oxide synthase immunoreactivity in hypothalamic nuclei of rats. 1218 45

Many histochemical investigations indicated that the oxytocin (OXY), the arginine vasopressin (AVP) and the nitric oxide synthase (NOS) have been synthesized in the supraoptic nucleus (SON) neurons. The objective of this study was to examine the age-related expression of the OXY, the AVP and the NOS in the SON of the young adult (2-month-old) and the aged (24-month-old) rats. The histochemistry for reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d; marker for the NOS) and the double labeling histochemistry for the OXY/NADPH-d or the AVP/NADPH-d were employed, and the quantitative analysis was performed with a computer-assisted image processing system. In comparison of the young adult and the aged group, the cell number, the cell size and the reactive density of the NOS-expressing neurons showed a significant increase along with age, and these evidences suggested the age-related increase of the nitric oxide (NO) production. The age-related significant increase was not detected in the number of the OXY/NOS-expressing neurons in the dorsal part, but was detected in the number of the AVP/NOS-expressing neurons in the ventral part. Based on our histochemical findings and reports demonstrated by other authors, we attempted to discuss the physiological role of NOS for the secretion of posterior pituitary hormones along with age.
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PMID:Age-related changes in oxytocin-, arginine vasopressin- and nitric oxide synthase-expressing neurons in the supraoptic nucleus of the rat. 1642 42

The topographic ontogeny of nitric oxide synthase (NOS) within the paraventricular nucleus (PVN) of the rat hypothalamus was studied by nicotinamide adenine dinucleotide-diaphorase (NADPH-diaphorase) histochemistry. At Day 1 of postnatal life (P1), NOS-positive neurons were already present and achieved their maturity (in terms of perikarya number and dendritic arborization) about the time of weaning (P21). Across all ages studied (P1 to adulthood), intense NADPH-diaphorase staining was primarily confined within magnocellular cells of the PVN largely characterized by medium-sized (12-15 mum in diameter), ovoid bipolar neurons with prominent clear nuclei. To identify the neurosecretory cells of the adult PVN in which NOS was present, double-labeling studies were carried out via fluorescent immunocytochemistry. Magnocellular oxytocin (OT) and arginine vasopressin (AVP), as well as parvocellular corticotropin-releasing factor (CRF), were found to be colocalized with NOS. However, colocalization occurred significantly more frequently in OT-containing neurons, relative to AVP- or CRF-positive cells. Most of the colocalization occurring between NOS and OT was observed in the rostral constituent of the magnocellular subdivision of the PVN, as opposed to a more caudal defined PVN. To provide a distribution comparison of OT, AVP, and CRF to that of NOS in the adult PVN, in situ hybridization was carried out with (35)S-cRNA antisense probes for the aforementioned neuropeptides. The results obtained with this evaluation were correlated with NOS histochemistry in the same brain sections. As expected, specific labeling was observed for all three neuroactive substances over their topographically distinctive nuclei. Among these nuclei, labeling by the OT cRNA probe provided the closest topographical correlation of hybridized signal over NOS perikarya, thus reinforcing the tenet that a relatively small population of OT nerve cells are concurrently colocalized with the enzyme. Taken together, these results indicate that NOS is present in the PVN of the rat at all postnatal ages which we tested. They also indicate that among neurosecretory cells of the PVN, only OT prominently shared with NOS the same common nerve cell type. This suggests that NOS neurons may represent a distinct neuropil group among multiple neuroactive nuclei in the neuroendocrine hypothalamus. Finally, we demonstrate that NADPH-diaphorase histochemistry can be easily combined with immunocytochemical and in situ hybridization procedures to evaluate the colocalization and topographical distribution of NOS with other phenotypic neurons in the mammalian central nervous system.
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PMID:Ontogeny of the rat hypothalamic nitric oxide synthase and colocalization with neuropeptides. 1991 18