Effect of catecholamine depletion and denervation on neuropeptide Y(NPY) and tyrosine-hydroxylase (TH) mRNA levels in rat sympathetic ganglia

Hänze, Jörg; Kummer, Wolfgang; Haass, Markus; Re, Lang

doi:10.1055/s-0029-1211266

Cited by 15 publications

(1 citation statement)

References 7 publications

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“…Previous studies showed that NPY gene expression is sensitive to both pharmacologic and physiological stimuli (20,26,63,72). IH-induced increase in preproNPY mRNA in the rat AM is reminiscent of a similar augmentation of pre-proNPY mRNA elicited by immobilization stress and pharmacologic interventions in rat sympathetic neurons (21,47) and the sympatho-adrenal system (26,38,63). Stress, in addition to stimulating neuronal input to the AM, increases circulating glucocorticoids.…”

Section: Ih and Prepronpy Mrna Expressionmentioning

confidence: 91%

Enhanced Neuropeptide Y Synthesis During Intermittent Hypoxia in the Rat Adrenal Medulla: Role of Reactive Oxygen Species–Dependent Alterations in Precursor Peptide Processing

Raghuraman

Kalari

Dhingra

et al. 2011

Antioxidants & Redox Signaling

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Intermittent hypoxia (IH) associated with recurrent apneas often leads to cardiovascular abnormalities. Previously, we showed that IH treatment elevates blood pressure and increases plasma catecholamines (CAs) in rats via reactive oxygen species (ROS)-dependent enhanced synthesis and secretion from the adrenal medulla (AM). Neuropeptide Y (NPY), a sympathetic neurotransmitter that colocalizes with CA in the AM, has been implicated in blood pressure regulation during persistent stress. Here, we investigated whether IH facilitates NPY synthesis in the rat AM and assessed the role of ROS signaling. IH increased NPY-like immunoreactivity in many dopamine-β-hydroxylase-expressing chromaffin cells with a parallel increase in preproNPY mRNA and protein. IH increased the activities of proNPY-processing enzymes, which were due, in part, to elevated protein expression and increased proteolytic processing. IH increased ROS generation, and antioxidants reversed IH-induced increases in ROS, preproNPY, and its processing to bioactive NPY in the AM. IH treatment increased blood pressure and antioxidants and inhibition of NPY amidation prevented this response. These findings suggest that IH-induced elevation in NPY expression in the rat AM is mediated by ROS-dependent augmentation of preproNPY mRNA expression and proNPY-processing enzyme activities and contributes to IH-induced elevation of blood pressure.

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Section: Ih and Prepronpy Mrna Expressionmentioning

confidence: 91%

Enhanced Neuropeptide Y Synthesis During Intermittent Hypoxia in the Rat Adrenal Medulla: Role of Reactive Oxygen Species–Dependent Alterations in Precursor Peptide Processing

Raghuraman

Kalari

Dhingra

et al. 2011

Antioxidants & Redox Signaling

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Rapid down-regulation of tyrosine hydroxylase expression in the olfactory bulb of naris-occluded adult rats

et al. 1996

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In most sensory systems, afferent innervation regulates morphological and biochemical characteristics of target cells for a limited time during development. Sensory deprivation experiments in adult rats also have suggested a critical period for afferent influences on olfactory bulb structure and function. Previous odorant deprivation studies that employed unilateral naris closure in neonatal rats demonstrated down-regulation of the catecholamine biosynthetic enzyme tyrosine hydroxylase (TH) in dopamine neurons intrinsic to the olfactory bulb. Accompanying the altered biochemical parameters was a decrease in bulb size. To distinguish between deprivation-induced alterations in TH expression secondary to developmental sequelae and those occurring in mature neurons, the consequences of unilateral naris closure were assessed in young adult rats. In agreement with previous studies significant postnatal increases occurred in TH expression and total protein, an indication of bulb size. At 30 days post-closure, total protein was unaltered in the ipsilateral olfactory bulb but showed a small (12.9%), significant decline at 60 days. In contrast to the limited morphological consequences of odor deprivation, profound reductions occurred in TH expression. TH activity ipsilateral to the closure decreased significantly by 14 days post-closure and remained depressed for up to 6 months. In parallel with enzyme activity, TH immunoreactivity did not decline in the first few days post-closure. In situ hybridization revealed that TH mRNA levels decreased rapidly, i.e., by 2 days post-closure, reached a nadir at 1 month, and remained depressed for at least 6 months. The capacity of odor deprivation in the adult rat olfactory system to down-regulate TH expression suggests that this phenotypic alteration occurs independently of a presumed critical period.

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Localization, regulation and functions of neurotransmitters and neuromodulators in cervical sympathetic ganglia

Klimaschewski

Kummer

Heym

1996

Microsc. Res. Tech.

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Effect of catecholamine depletion and denervation on neuropeptide Y(NPY) and tyrosine-hydroxylase (TH) mRNA levels in rat sympathetic ganglia

Cited by 15 publications

References 7 publications

Enhanced Neuropeptide Y Synthesis During Intermittent Hypoxia in the Rat Adrenal Medulla: Role of Reactive Oxygen Species–Dependent Alterations in Precursor Peptide Processing

Enhanced Neuropeptide Y Synthesis During Intermittent Hypoxia in the Rat Adrenal Medulla: Role of Reactive Oxygen Species–Dependent Alterations in Precursor Peptide Processing

Rapid down-regulation of tyrosine hydroxylase expression in the olfactory bulb of naris-occluded adult rats

Localization, regulation and functions of neurotransmitters and neuromodulators in cervical sympathetic ganglia

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