Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.1 (NADPH-diaphorase)
 3,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma arginine vasopressin (AVP) is known to be elevated in patients with uncontrolled insulin-dependent diabetes mellitus who have plasma hyperosmolality with hyperglycaemia. Although osmotic stimuli cause an increase in nitric oxide synthase (NOS) activity as well as synthesis of AVP and oxytocin in the paraventricular (PVN) and supraoptic nuclei (SON), it is not known whether NOS activity in the hypothalamus changes in the diabetic patients who have plasma hyperosmolality with hyperglycaemia caused by insulin deficiency. Expression of the neuronal (n) NOS gene in the PVN and SON in streptozotocin (STZ)-induced diabetic rats was investigated by using in situ hybridization histochemistry and NADPH-diaphorase histochemical staining. Four weeks after intraperitoneal (i. p.) administration of STZ, male Wistar rats developed hyperglycaemia and plasma hyperosmolality. The expression of nNOS gene and NADPH-diaphorase staining in the PVN and SON remarkably increased in STZ-induced diabetic rats compared to control rats. Three weeks after administration of STZ, the diabetic rats were subcutaneously treated with insulin for 1 week, which resulted in significant suppression of the induction of nNOS, AVP and oxytocin gene expression in the PVN and SON. Furthermore, the induction of nNOS gene expression in the PVN and SON was suppressed in STZ-induced diabetic rats treated with phlorizin and diet to normalize hyperglycaemia without insulin treatment. These results suggest that upregulation of nNOS gene expression as well as AVP and oxytocin gene expression in the PVN and SON in STZ-induced diabetic rats may be associated with hyperglycaemia and plamsa hyperosmolality.
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PMID:Upregulation of hypothalamic nitric oxide synthase gene expression in streptozotocin-induced diabetic rats. 966 44

To clarify the role of nitric oxide (NO) in the ontogeny of arginine vasopressin (AVP) and oxytocin (OXT) neurons in the hypothalamo-neurohypophysial system (HNS), we observed the coexpression pattern of NADPH-diaphorase (NADPH-d) activity and AVP- or OXT-immunoreactivity (IR) in the rat hypothalamus and posterior pituitary during the postnatal period. The enzymatic activity of NADPH-d was observed in the supraoptic nucleus (SON), paraventricular nucleus (PVN), median eminence (ME) and posterior pituitary throughout the postnatal development. AVP-containing neurons were clearly observed from postnatal day 1 in both the SON and PVN, while OXT-containing neurons were recognized from postnatal day 14. The coexistence of NADPH-d and AVP or OXT was detected in the SON from postnatal day 14. At postnatal day 21, the coexpression pattern was approximately the same as that of the SON and PVN in adult rats. Our findings indicated that the expression of NADPH-d and OXT was observed from almost the same postnatal period in both the SON and PVN. In addition, the pattern of increased numbers of NADPH-d positive fibers was similar to that of OXT-immunoreactive fibers in both the inner layer of the ME and the posterior pituitary. A good correlation was thus obtained between OXT expression and NADPH-d activity in the HNS during postnatal development. The present study suggests that NO is more closely involved in the expression and regulation of secretion of OXT than AVP.
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PMID:Postnatal development of NADPH-diaphorase activity in the rat: the role of nitric oxide in the ontogeny of arginine vasopression and oxytocin. 1120 Sep 42

The anatomical distribution and quantitative relations of cell bodies containing neuronal nitric oxide synthase (nNOS), 8-arginine vasopressin (AVP) and oxytocin (OT) were examined throughout the supraoptic nucleus (SON) of the female rat by means of immunocytochemical and NADPH-diaphorase (NADPH-d) histochemical techniques using a triple labelling methodology. Seven chemically defined populations of neurons containing all combinations of either nNOS, AVP or OT were identified. nNOS-containing (NADPH-d positive) neurons, amounting to about 40% of all neurons counted, were most frequent in central and dorsal regions, and were evenly distributed along the rostro-caudal axis. Two small nNOS-positive neuronal populations were preferentially located dorso-centrally in the nucleus: nNOS-positive neurons containing both AVP- and OT-immunoreactivity, and neurons only containing nNOS. Slightly less than half of all nNOS-positive neurons contained AVP, and a similar share of nNOS-positive neurons contained OT. The occurrence of nNOS-positive/AVP-containing neurons was highest in the caudal half, whereas that of nNOS-positive/OT-neurons was highest in the rostral half of SON. The data demonstrate new findings concerning the anatomical organization and co-localization patterns of nNOS-, AVP- and OT-containing neuronal populations in SON. We conclude that the absolute and relative occurrence of the identified neuronal populations vary markedly in different parts of SON. This is important to take into consideration when performing, and evaluating experimental investigations concerned with neurochemical changes in SON.
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PMID:Detailed organization of nitric oxide synthase, vasopressin and oxytocin immunoreactive cell bodies in the supraoptic nucleus of the female rat. 1139 57

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