Linked Life Data

18443753

Source:http://linkedlifedata.com/resource/pubmed/id/18443753

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-5-9
pubmed:abstractText
Angiotensin II (AngII) is a major culprit in essential hypertension. Based on a genetic rodent model of hypertension, we review here evidence that AngII may signal across the blood brain barrier to affect neuronal circuits within the nucleus tractus solitarii (NTS) of the brainstem, a pivotal region regulating both the baroreceptor reflex and set point control of arterial pressure. We have termed this form of signalling as vascular-neuronal signalling. We describe that the depressant action of AngII in NTS on the baroreceptor reflex is mediated via activation of endothelial nitric oxide synthase (eNOS) releasing NO that promotes release of the inhibitory transmitter-GABA. This could shunt the incoming excitatory baroreceptor afferent traffic impinging on NTS neurones. Chronic studies recording arterial pressure in conscious unrestrained rats using radio-telemetry have revealed that eNOS in NTS plays an endogenous physiological role in the homeostatic regulation of the gain of the cardiac baroreceptor reflex. However, in the spontaneously hypertensive rat, eNOS mRNA was higher (compared to normotensive rats), and its chronic blockade in NTS restored the abnormally depressed cardiac baroreceptor reflex to levels akin to normotensive rats, improved heart rate variability and lowered arterial pressure. Hence, it seems that excessive eNOS activity in NTS of the SHR contributes to the pathological state of this animal model's cardiovascular autonomic nervous system. We speculate on why eNOS activity may be up regulated in the NTS of the SHR and propose that it is a consequence of high cerebral vascular resistance and inadequate blood perfusion of the brainstem.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0946-2716
pubmed:author
pubmed:issnType
Print
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
705-10
pubmed:dateRevised
2011-7-8
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Signalling across the blood brain barrier by angiotensin II: novel implications for neurogenic hypertension.
pubmed:affiliation
Department of Physiology & Pharmacology, Bristol Heart Institute, School of Medical Sciences, University of Bristol, Bristol, UK. Julian.F.R.Paton@Bristol.ac.uk
pubmed:publicationType
Journal Article, Review, Research Support, Non-U.S. Gov't