A common neuronal mechanism of hypertension and sleep disturbances in spontaneously hypertensive rats: Role of orexinergic neurons

Chronic Stress-Induced Elevation of Melanin-Concentrating Hormone in the Locus Coeruleus Inhibits Norepinephrine Production and Associated With Depression-Like Behaviors in Rats

BACKGROUND

Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide that projects throughout the central nervous system, including the noradrenergic locus coeruleus (LC). Our previous study suggested that MCH/MCH receptor 1 (MCHR1) in the LC may be involved in the regulation of depression. The present study investigated whether the role of MCH/MCHR1 in the LC in depression-like behaviors is associated with the regulation of norepinephrine.

METHOD

Chronic unpredictable stress (CUS) and an acute intra-LC microinjection of MCH induced depression-like behaviors in rats. The MCHR1 antagonist SNAP-94847 was also microinjected in the LC in rats that were suffering CUS or treated with MCH. The sucrose preference, forced swim, and locomotor tests were used for behavioral evaluation. Immunofluorescence staining, enzyme-linked immunosorbent assay, western blot, and high-performance liquid chromatography with electrochemical detection were used to explore the mechanism of MCH/MCHR1 in the regulation of depression-like behaviors.

RESULTS

CUS induced an abnormal elevation of MCH levels and downregulated MCHR1 in the LC, which was highly correlated with the formation of depression-like behaviors. SNAP-94847 exerted antidepressant effects in CUS-exposed rats by normalizing tyrosine hydroxylase, dopamine β hydroxylase, and norepinephrine in the LC. An acute microinjection of MCH induced depression-like behaviors through its action on MCHR1. MCHR1 antagonism in the LC significantly reversed the MCH-induced downregulation of norepinephrine production by normalizing MCHR1-medicated cAMP-PKA signaling.

CONCLUSIONS

Our study confirmed that the MCH/MCHR1 system in the LC may be involved in depression-like behaviors by downregulating norepinephrine production. These results improve our understanding of the pathogenesis of depression that is related to the MCH/MCHR1 system in the LC.

Acupuncture combined with western medicine for the treatment of hypertension: A protocol for an updated systematic review and meta-analysis

BACKGROUND

Hypertension is a kind of cardiovascular syndrome with the main clinical manifestation of continuous increase of systemic arterial blood pressure. Hypertension coexists with other cardiovascular risk factors and is an important risk factor for cardiovascular and cerebrovascular diseases. Acupuncture is an important part of Traditional Chinese Medicine intervention. The antihypertensive effect of acupuncture on hypertension is based on the neuroendocrine system, characterized by multichannel and multitarget. This study aims to provide latest and updated proof of systematic review to assess the effectiveness and safety of acupuncture for hypertension.

METHODS

We will systematically search 9 databases from their inceptions to February 2021. Only randomized controlled trials of acupuncture combined with western medicine in the treatment of hypertension will meet the inclusion criteria. The main outcome measures we focus on include clinical efficacy, syndrome efficacy, Traditional Chinese Medicine syndrome score, diastolic and systolic blood pressure changes, blood pressure variability, heart rate variability, pulse rate variability, and adverse reactions. The research screening, data extraction, and risk of bias assessment will be employed by 2 reviewers independently, and disagreement will be decided by a third senior reviewer. The Revman 5.3 software will be used for meta-analysis. The confidence of proof will be rated adopting grading of recommendations assessment, development and evaluation tool and methodological quality of this research will be assessed using assessment of multiple systematic reviews-2 and risk of bias in systematic reviews. The publication quality will be evaluated by preferred reporting items for systematic reviews and meta-analyses (PRISMA).

RESULTS

This systematic review (SR) will provide evidence-based medical evidence for hypertension therapy by acupuncture combined with western medicine and we will submit the findings of this SR for peer-review publication.

CONCLUSIONS

This SR will provide latest and updated summary proof for assessing the effectiveness and safety of acupuncture for hypertension.

REGISTRATION NUMBER

INPLASY 202150047.

Roles of central orexinergic system on cardiovascular function and acupuncture on intervention of cardiovascular risk: Orexinergic system mediate the role of acupuncture?

Central orexinergic system contributes to the regulation of cardiovascular function. Orexinergic neurons receiving projections of nerve fibers from multiple structures of brain which involved in control and regulation of cardiovascular function locate in hypothalamus, and their axon terminals widely project to various central structures where orexins receptors are expressed. Here, we summarize the present knowledge that describes the influence of central orexinergic system on cardiovascular activity, the relevance of dysfunction in central orexinergic system with hypertension and psychological stress induced cardiovascular reactivity which are serious risk factors for cardiovascular disease and cardiovascular death. We propose that central orexinergic system may be potentially important targets for the prevention of cardiovascular disease and cardiovascular death, and different orexinergic system involved neuronal circuits may be involved in distinct cardiovascular functions. Acupuncture having bidirectional regulatory ability and a much lower incidence of side effects can prevent disease. We review the improvement of acupuncture on hypertension and psychological stress induced cardiovascular reactivity. We think that acupuncture intervenes hypertension and psychological stress induced cardiovascular reactivity to prevent cardiovascular disease and cardiovascular death. We also summarize relation between acupuncture and central orexinergic system. We propose a hypothesis that acupuncture improve hypertension and psychological stress induced cardiovascular reactivity through regulating central orexinergic system. The knowledge is beneficial for the development of potential therapeutic targets and methods to prevent cardiovascular disease and cardiovascular death.