Faculty Collaboration Database

Expression of smooth muscle myosin heavy chains and unloaded shortening in single smooth muscle cells. Am J Physiol 1997 Oct;273(4):C1259-66

Date

11/14/1997

Pubmed ID

9357770

DOI

10.1152/ajpcell.1997.273.4.C1259

Scopus ID

2-s2.0-0030662128 (requires institutional sign-in at Scopus site)   31 Citations

Abstract

The functional significance of the variable expression of the smooth muscle myosin heavy chain (SM-MHC) tail isoforms, SM1 and SM2, was examined at the mRNA level (which correlates with the protein level) in individual permeabilized rabbit arterial smooth muscle cells (SMCs). The length of untethered single permeabilized SMCs was monitored during unloaded shortening in response to increased Ca2+ (pCa 6.0), histamine (1 microM), and phenylephrine (1 microM). Subsequent to contraction, the relative expression of SM1 and SM2 mRNAs from the same individual SMCs was determined by reverse transcription-polymerase chain reaction amplification and densitometric analysis. Correlational analyses between the SM2-to-SM1 ratio and unloaded shortening in saponin- and alpha-toxin-permeabilized SMCs (n = 28) reveal no significant relationship between the SM-MHC tail isoform ratio and unloaded shortening velocity. The best correlations between SM2/SM1 and the contraction characteristics of untethered vascular SMCs were with the minimum length attained following contraction (n = 20 and r = 0.72 for alpha-toxin, n = 8 and r = 0.78 for saponin). These results suggest that the primary effect of variable expression of the SM1 and SM2 SM-MHC tail isoforms is on the cell final length and not on shortening velocity.

Author List

Meer DP, Eddinger TJ

Author

Thomas Eddinger PhD Bioological Sciences in the Biology department at Marquette University

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

Animals
Aorta
Calcium
Carotid Arteries
Cell Membrane Permeability
Cells, Cultured
Histamine
Muscle Contraction
Muscle, Smooth, Vascular
Myosin Heavy Chains
Phenylephrine
Polymerase Chain Reaction
RNA, Messenger
Rabbits
Regression Analysis
Saponins
Time Factors
Transcription, Genetic
Type C Phospholipases