HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Correspondence: Submit a response Alert me when this article is cited Alert me when Correspondence are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by McCALDEN, T. A. Articles by EIDELMAN, B. H. Search for Related Content PubMed PubMed Citation Articles by McCALDEN, T. A. Articles by EIDELMAN, B. H.

Cerebrovascular response to infused noradrenalin and its modification by a catecholamine metabolism blocker

From the Department of Physiology, Medical School, University of the Witwatersrand, Johannesburg, South Africa.

Despite many studies, the cerebrovascular action of infused noradrenalin is still unclear. The study reported here tested the hypothesis that infused noradrenalin is prevented from reaching the adrenoreceptors by being avidly taken up and metabolized in the vascular smooth muscle. Cerebral blood flow was measured by the xenon¹³³ clearance technique in nine baboons before and during blockade of the enzyme catechol-O-methyl transferase, which is known to be important in inactivation of circulating noradrenalin. The cerebral blood flow responses to noradrenalin infused at 8, 16, and 32 µg per minute were also determined. Responses indicated vasodilatation before but vasoconstriction after blockade, with a significant difference at the 8 (p < 0.025) and 16 (p < 0.05) µg per minute doses of noradrenalin. It is suggested that the cerebral circulation is normally protected against sympathetic vasoconstriction by the avid uptake and metabolism of noradrenalin in extraneuronal and possibly neuronal sites.

Dr. McCalden's address is Department of Physiology, Medical School, University of witwatersrand, Hospital St., Johannesburg, South Africa.

This study was supported by grants from the medical Research council and the Atomic Energy Board

Received for publication October 25, 1975.

This article has been cited by other articles:

				I. K. Moppett, M. J. Wild, R. W. Sherman, J. A. Latter, K. Miller, and R. P. Mahajan Effects of ephedrine, dobutamine and dopexamine on cerebral haemodynamics: transcranial Doppler studies in healthy volunteers Br. J. Anaesth., January 1, 2004; 92(1): 39 - 44. [Abstract] [Full Text] [PDF]