Nitric oxide and GABA mediate bi-directional cardiovascular effects of orexin in the nucleus tractus solitarii of rats

Shih, Cheng-Dean; Chuang, Yao-Chung

doi:10.1016/j.neuroscience.2007.07.016

Cited by 54 publications

(41 citation statements)

References 41 publications

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“…The fact that administration of a GABA agonist led to protection after lethal ischemia (Dave et al, 2005), whereas blockade of GABA receptors abolished IPCmediated protection , confirms the protective role of GABA activity against ischemic injury in the brain. IPC has also been shown to increase inducible NOS in cardiac myocytes (Wang et al, 2002), and the effects of NO on GABA modulation have been linked to the regulation of cardiac properties (Shih and Chuang, 2007). In the hippocampus, GABA synapse activity was modulated in a protective manner by epsilon protein kinase C (ePKC) , an important signaling cascade activated by IPC.…”

Section: Ischemic Preconditioning Activates Sirt1 and Protects Againsmentioning

confidence: 99%

Pathways for Ischemic Cytoprotection: Role of Sirtuins in Caloric Restriction, Resveratrol, and Ischemic Preconditioning

Morris

Lin

Thompson

et al. 2011

J Cereb Blood Flow Metab

120

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Caloric restriction (CR), resveratrol, and ischemic preconditioning (IPC) have been shown to promote protection against ischemic injury in the heart and brain, as well as in other tissues. The activity of sirtuins, which are enzymes that modulate diverse biologic processes, seems to be vital in the ability of these therapeutic modalities to prevent against cellular dysfunction and death. The protective mechanisms of the yeast Sir2 and the mammalian homolog sirtuin 1 have been extensively studied, but the involvement of other sirtuins in ischemic protection is not yet clear. We examine the roles of mammalian sirtuins in modulating protective pathways against oxidative stress, energy depletion, excitotoxicity, inflammation, DNA damage, and apoptosis. Although many of these sirtuins have not been directly implicated in ischemic protection, they may have unique roles in enhancing function and preventing against stress-mediated cellular damage and death. This review will include in-depth analyses of the roles of CR, resveratrol, and IPC in activating sirtuins and in mediating protection against ischemic damage in the heart and brain.

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Section: Ischemic Preconditioning Activates Sirt1 and Protects Againsmentioning

confidence: 99%

Pathways for Ischemic Cytoprotection: Role of Sirtuins in Caloric Restriction, Resveratrol, and Ischemic Preconditioning

Morris

Lin

Thompson

et al. 2011

J Cereb Blood Flow Metab

120

View full text Add to dashboard Cite

show abstract

“…promotes lipolysis through facilitation of the sympathetic nervous system [52]. Moreover, low-dose of orexin A (10 ng i.v., 0.01 ng i.c.v., or 5 pmol into NTS) evokes a cardiovascular suppressive effect, whereas high-dose of orexin A (1000 ng i.v., 10 ng i.c.v., or >20 pmol into NTS) conversely induces the cardiovascular excitatory effects [53,54].…”

Section: The Blood Glucose-lowering Effect Of Orexinmentioning

confidence: 99%

Role of orexin in the central regulation of glucose and energy homeostasis [Review]

2012

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Abstract. Hypothalamic orexin neurons are known to regulate sleep/wake stability, feeding behavior, emotions, autonomic nerve activity, and whole-body energy metabolism. In addition, emerging evidence indicates that orexin contributes to central regulation of glucose homeostasis. Intriguingly, central administration of orexin is reported to cause blood glucoseelevating effect or blood glucose-lowering effect in rodents, depending on the experimental conditions. Here we reviewed the recent reports regarding the mode and mechanism of actions of orexin on these two opposing effects, and discuss the functional significance for the maintenance of glucose homeostasis. The fact that orexin exhibits biphasic effects on autonomic nerve activity and lipolysis suggests that orexin dually regulates the glucose appearance. In fact, orexin neurons are activated not only depending on the demand for glucose but also according to a circadian rhythm in the suprachiasmatic nucleus. The excited orexin neurons appear to alter the sympathetic or parasympathetic outflow to the periphery, and modulate the glucose production and utilization. Furthermore, deficiency of orexin action, particularly reduction of orexin 2 receptor-signaling, disrupts the mechanism for protection against insulin resistance associated with aging or induced by chronic high fat feeding in mice. Taken together, hypothalamic orexin system may manage multiple tasks to coordinate the interconnection among the arousal, feeding, circadian, and glucose homeostasis pathways.

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“…The orexin innervation of the nucleus of the solitary tract might serve as the anatomical substrate for the involvement of orexins in the regulation of cardiovascular functions [Smith et al, 2002b;de Oliveira et al, 2003;Shih and Chuang, 2007].…”

Section: Possible Relationships Between the Orexinergic And Monoaminementioning

confidence: 99%

Distribution of Orexin/Hypocretin Immunoreactivity in the Brain of the Lungfishes <i>Protopterus dolloi</i> and <i>Neoceratodus forsteri</i>

et al. 2009

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Lungfishes are currently considered the closest living relatives of tetrapods and represent an interesting group for the study of evolutionary traits in the transition from fishes to tetrapods. The brains of lungfishes have received little attention in comparative studies probably due to the difficulty of obtaining these unique animals. In the present study the distribution of orexin (hypocretin)-like immunoreactivity was studied in the brain of the African lungfish Protopterus dolloi and the Australian lungfish Neoceratodus forsteri by using antibodies directed against the mammalian orexin-A and orexin-B peptides. Simultaneous detection of orexins and tyrosine hydroxylase or serotonin was used to assess the precise location of the orexins in the brain and to evaluate the possible influence of the orexin system on the monoaminergic cell groups. Although some differences were noted, a common pattern for the distribution of orexins in the two lungfishes studied was observed. In both species, most immunoreactive neurons were observed in the suprachiasmatic nucleus and dorsal hypothalamus. Only in Neoceratodus, however, were important cell populations found in the preoptic area and infundibular hypothalamus, whereas small numbers of faintly reactive neurons were present in the lateral septum and ventral striatum. Fiber labeling was widely distributed in all main brain subdivisions, but was more abundant in regions such as the septum, preoptic area, suprachiasmatic nucleus, lateral hypothalamic area, thalamus, pretectum and tegmentum. Less conspicuous was the innervation of the pallial regions, habenula, optic tectum, rhombencephalic reticular formation and spinal cord. Orexinergic innervation was found in close contact with dopaminergic, noradrenergic and serotoninergic cell groups, homologous to the substantia nigra in the midbrain tegmentum, the locus coeruleus, the nucleus of the solitary tract and the raphe nuclei. Although unique features have been found for lungfishes, the location of orexin immunoreactive elements is largely consistent with that recently reported following a similar approach in amphibians and amniotes, suggesting that the general organization of this peptidergic system occurred in the common ancestor of lungfishes and tetrapods.

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Nitric oxide and GABA mediate bi-directional cardiovascular effects of orexin in the nucleus tractus solitarii of rats

Cited by 54 publications

References 41 publications

Pathways for Ischemic Cytoprotection: Role of Sirtuins in Caloric Restriction, Resveratrol, and Ischemic Preconditioning

Pathways for Ischemic Cytoprotection: Role of Sirtuins in Caloric Restriction, Resveratrol, and Ischemic Preconditioning

Role of orexin in the central regulation of glucose and energy homeostasis [Review]

Distribution of Orexin/Hypocretin Immunoreactivity in the Brain of the Lungfishes <i>Protopterus dolloi</i> and <i>Neoceratodus forsteri</i>

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