Effect of skeletal muscle fiber type on the pressor response evoked by static contraction in rabbits.

Published

Journal Article

The purpose of this study was to determine whether the reflex hemodynamic responses to static contraction of predominately glycolytic muscle are greater than the changes elicited by primarily oxidative muscle. Low-frequency electrical stimulation (continuous 21 days) of the tibial nerve of one hindlimb of adult rabbits converted the metabolic characteristics of the predominately glycolytic gastrocnemius to a muscle that was primarily oxidative. After 21 days of stimulation, the rabbits were decerebrated, and static contraction of the glycolytic muscle (unstimulated gastrocnemius) initially decreased heart rate (HR; -16 +/- 3 beats/min) and mean arterial pressure (MAP; -17 +/- 3 mmHg). Thereafter, MAP increased 13 +/- 3 mmHg above baseline. Static contraction of the oxidative muscle (stimulated gastrocnemius) produced similar decreases in HR and MAP (-12 +/- 4 beats/min and -12 +/- 3 mmHg, respectively). However, the subsequent increase in MAP (8 +/- 3 mmHg; above baseline) was less than that evoked by contraction of the glycolytic muscle. The responses evoked by stretch of each muscle and high-intensity electrical stimulation were the same, indicating that the afferents from the muscle were not destroyed by the chronic-stimulation technique. These results support the hypothesis that metabolic by-products play a role in the pressor response to static contraction of skeletal muscle. In addition, these data confirm that contraction of predominately oxidative muscle can evoke a reflex pressor response, albeit smaller than the change elicited from primarily glycolytic muscle.

Full Text

Duke Authors

Cited Authors

  • Wilson, LB; Dyke, CK; Parsons, D; Wall, PT; Pawelczyk, JA; Williams, RS; Mitchell, JH

Published Date

  • November 1995

Published In

Volume / Issue

  • 79 / 5

Start / End Page

  • 1744 - 1752

PubMed ID

  • 8594037

Pubmed Central ID

  • 8594037

International Standard Serial Number (ISSN)

  • 8750-7587

Digital Object Identifier (DOI)

  • 10.1152/jappl.1995.79.5.1744

Language

  • eng

Conference Location

  • United States