Faculty Collaboration Database

Preferential myosin heavy chain isoform B Expression may contribute to the faster velocity of contraction in veins versus arteries. J Vasc Res 2007;44(4):264-72

Date

03/23/2007

Pubmed ID

17377397

DOI

10.1159/000100991

Scopus ID

2-s2.0-34250789615 (requires institutional sign-in at Scopus site)   5 Citations

Abstract

Smooth muscle myosin heavy chains occur in 2 isoforms, SMA (slow) and SMB (fast). We hypothesized that the SMB isoform is predominant in the faster-contracting rat vena cava compared to thoracic aorta. We compared the time to half maximal contraction in response to a maximal concentration of endothelin-1 (ET-1; 100 nM), potassium chloride (KCl; 100 mM) and norepinephrine (NE; 10 microM). The time to half maximal contraction was shorter in the vena cava compared to aorta (aorta: ET-1 = 235.8 +/- 13.8 s, KCl = 140.0 +/- 33.3 s, NE = 19.8 +/- 2.7 s; vena cava: ET-1 = 121.8 +/- 15.6 s, KCl = 49.5 +/- 6.7 s, NE = 9.0 +/- 3.3 s). Reverse-transcription polymerase chain reaction supported the greater expression of SMB in the vena cava compared to aorta. SMB was expressed to a greater extent than SMA in the vessel wall of the vena cava. Western analysis determined that expression of SMB, relative to total smooth muscle myosin heavy chains, was 12.5 +/- 4.9-fold higher in the vena cava compared to aorta, while SMA was 4.9 +/- 1.2-fold higher in the aorta than vena cava. Thus, the SMB isoform is the predominant form expressed in rat veins, providing one possible mechanism for the faster response of veins to vasoconstrictors.

Author List

Rondelli CM, Szasz IT, Kayal A, Thakali K, Watson RE, Rovner AS, Eddinger TJ, Fink GD, Watts SW

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, Thoracic
Blotting, Western
Endothelin-1
Gene Expression
Male
Muscle Contraction
Myosin Heavy Chains
Norepinephrine
Potassium Chloride
RNA, Messenger
Rats
Rats, Sprague-Dawley
Vasoconstriction
Vasoconstrictor Agents
Venae Cavae