PMID: 6163406Oct 1, 1980Paper

Effects of medullary pyramidal stimulation on myocardial contractility in anesthetized dogs

Archives internationales de physiologie et de biochimie
M J MathiotP Zwirn

Abstract

In anaesthetized dogs, medullary pyramid stimulation produces a decrease of myocardial contractility. The peak of the first derivative of the left ventricular pressure (dP/dt max) was used to assess myocardial contractility; this index is independent of afterload. Medullary pyramid stimulation produces a decrease of dP/dt max and of the maximal left ventricular pressure (L.V.P. max) also, after bilateral vagotomy. But the same stimulation induces only a decrease of L.V.P. max after inhibiting beta-adrenergic efferences and bilateral vagotomy. Just as corticopyramidal fibres inhibiting alpha-adrenergic vascular tone, one does consider the existence of corticopyramidal fibres inhibiting beta-adrenergic efferences to myocardium.

References

Jan 13, 1977·The New England Journal of Medicine·E Braunwald
May 1, 1953·Journal of Neurophysiology·W M LANDAU
Jan 1, 1962·The Journal of Clinical Investigation·W L GLEASON, E BRAUNWALD
Jul 1, 1963·The American Journal of Physiology·A G WALLACEJ H MITCHELL
May 30, 1950·Acta Physiologica Scandinavica·B FOLKOW, B UVNAS

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