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dc.contributor.authorRamchandra, R
dc.contributor.authorHood, SG
dc.contributor.authorFrithiof, R
dc.contributor.authorMcKinley, MJ
dc.contributor.authorMay, CN
dc.identifierpii: jphysiol.2012.236059
dc.identifier.citationRamchandra, R., Hood, S. G., Frithiof, R., McKinley, M. J. & May, C. N. (2013). The role of the paraventricular nucleus of the hypothalamus in the regulation of cardiac and renal sympathetic nerve activity in conscious normal and heart failure sheep. JOURNAL OF PHYSIOLOGY-LONDON, 591 (1), pp.93-107.
dc.descriptionC1 - Journal Articles Refereed
dc.description.abstractThe paraventricular nucleus of the hypothalamus (PVN) plays a major role in central cardiovascular and volume control, and has been implicated in controlling sympathetic nerve activity (SNA) during volume expansion and in heart failure (HF). The objectives were to determine the role of the PVN on cardiac and renal SNA (CSNA and RSNA) in conscious normal sheep and sheep with pacing-induced heart failure. In normovolaemic sheep in the normal state and in HF, bilateral microinjection of the GABA agonist muscimol (2 mm, 500 nl), had no effects on resting mean arterial pressure (MAP), heart rate (HR), CSNA or RSNA. In addition, neither chemical inhibition of the PVN using the inhibitory amino acid glycine (0.5 m, 500 nl), nor electrolytic lesion of the PVN reduced the elevated level of CSNA in HF. Dysinhibition of the PVN with bilateral microinjection of bicuculline (1 mm, 500 nl) in normal sheep increased MAP, HR and CSNA, but decreased RSNA, whereas in HF bicuculline had no effects on MAP, HR or CSNA, but inhibited RSNA. During volume expansion in normal sheep, muscimol reversed the inhibition of RSNA, but not of CSNA. In summary, removal of endogenous GABAergic inhibition to the PVN indicated that CSNA is normally under inhibitory control. Although this inhibition was absent in HF, the responses to pharmacological inhibition, or lesion of the PVN, indicates that it does not drive the increased CSNA in HF. These findings indicate the PVN has a greater influence on RSNA than CSNA in the resting state in normal and HF sheep, and during volume expansion in normal sheep.
dc.subjectNeurosciences not elsewhere classified; Cardiology (incl. Cardiovascular Diseases); Veterinary Sciences not elsewhere classified; Expanding Knowledge in the Medical and Health Sciences; Expanding Knowledge in the Agricultural and Veterinary Sciences; Cardiovascular System and Diseases
dc.titleThe role of the paraventricular nucleus of the hypothalamus in the regulation of cardiac and renal sympathetic nerve activity in conscious normal and heart failure sheep
dc.typeJournal Article
melbourne.peerreviewPeer Reviewed
melbourne.affiliationThe University of Melbourne
melbourne.affiliation.departmentFlorey Department Of Neuroscience And Mental Health
melbourne.source.titleJOURNAL OF PHYSIOLOGY-LONDON
melbourne.contributor.authorRAMCHANDRA, ROHIT
melbourne.contributor.authorMay, Clive
melbourne.contributor.authorMcKinley, Michael
melbourne.identifier.fundernameidNHMRC, 628573
melbourne.identifier.fundernameidNHMRC, 350328
melbourne.identifier.fundernameidNHMRC, 566819
melbourne.fieldofresearch320999 Neurosciences not elsewhere classified
melbourne.fieldofresearch320101 Cardiology (incl. cardiovascular diseases)
melbourne.seocode280103 Expanding knowledge in the biomedical and clinical science
melbourne.seocode280101 Expanding knowledge in the agricultural, food and veterinary sciences
melbourne.seocode200199 Clinical health not elsewhere classified
melbourne.accessrightsAccess this item via the Open Access location

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