Plasma catecholamines and neuropeptide-Y as indices of sympathetic nerve activity in normotensive and stroke-prone spontaneously hypertensive rats

P. R.C. Howe, P. F. Rogers, M. J. Morris, J. P. Chalmers, R. M. Smith

    Research output: Contribution to journalArticle

    66 Citations (Scopus)

    Abstract

    The suitability of plasma catecholamines (CAs) and neuropeptide-Y (NPY) as biochemical indices of sympathetic nerve activity (SNA) has been investigated, and these parameters have been compared between adult normotensive (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). Plasma norepinephrine (NE), epinephrine (E) and NPY were measured in venous and arterial blood samples taken from conscious, unrestrained rats. Under resting conditions, both CAs were significantly higher in SHRSP than in WKY; plasma E in particular was raised threefold. SHRSP had higher plasma levels of NPY in arterial blood but not in venous blood. Acute hydralazine-induced hypotension caused a slight rise in NPY and striking increases of CAs, which were accentuated in SHRSP. Ganglion blockade with pentolinium reversed these increases but the differences in basal plasma CA levels between strains still persisted. Barbiturate anaesthesia had little effect on plasma levels of NPY or NE, but plasma E levels were depressed, particularly in SHRSP, so that the strain difference in plasma E taken from venous blood was no longer apparent. The results indicate that plasma levels of CAs but not NPY are useful indices of SNA in conscious rats. Comparisons between WKY and SHRSP after drug treatment demonstrate a major contribution by the adrenal medulla to plasma CA levels in SHRSP which, under resting conditions, may not be sympathetically evoked.

    Original languageEnglish
    Pages (from-to)1113-1121
    Number of pages9
    JournalJournal of Cardiovascular Pharmacology
    Volume8
    Issue number6
    DOIs
    Publication statusPublished - Nov 1986

    Fingerprint Dive into the research topics of 'Plasma catecholamines and neuropeptide-Y as indices of sympathetic nerve activity in normotensive and stroke-prone spontaneously hypertensive rats'. Together they form a unique fingerprint.

  • Cite this