Faculty Collaboration Database

Axial stretching of extremity artery induces reversible hyperpolarization of smooth muscle cell membrane in vivo. Acta Physiol Hung 2001;88(3-4):197-206

Date

08/07/2002

Pubmed ID

12162578

DOI

10.1556/APhysiol.88.2001.3-4.2

Scopus ID

2-s2.0-0035552354 (requires institutional sign-in at Scopus site)   3 Citations

Abstract

Circumferential stretch due to increases in pressure induces vascular smooth muscle cell depolarization and contraction known as the myogenic response. The aim of this study was to determine the in vivo effects of axial-longitudinal stretch of the rat saphenous artery (SA) on smooth muscle membrane potential (Em) and on external diameter. Consecutive elongations of the SA were carried out from resting length (L0) in 10% increments up to 140% L0 while changes in membrane potential and diameter were determined in intact and de-endothelized vessels. Axial stretching resulted in a small initial depolarization at 120% of L0 followed by a progressive 20 to 33% hyperpolarizaion of vascular smooth muscle between 130% and 140% of L0. At 140%, an average maximal 10.6 mV reversible hyperpolarization was measured compared to -41.2 +/- 0.49 mV Em at 100% L0. De-endothelialization completely eliminated the hyperpolarization to axial stretching and augmented the reduction of diameter beyond 120% L0. These results indicate that arteries have a mechanism to protect them from vasospasm that could otherwise occur with movements of the extremities.

Author List

Monos E, Raffai G, Contney SJ, Stekiel WJ, Cowley AW Jr

Author

Allen W. Cowley Jr PhD Professor in the Physiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Arteries
Endothelium, Vascular
Male
Membrane Potentials
Micromanipulation
Muscle Tonus
Muscle, Smooth, Vascular
Rats
Rats, Sprague-Dawley
Stress, Mechanical