Display options
Cite
Driska SP, Stein PG, Porter R. Myosin dephosphorylation during rapid relaxation of hog carotid artery smooth muscle. Am J Physiol. 1989;256(2):C315-21doi: 10.1152/ajpcell.1989.256.2.C315.
Driska, S. P., Stein, P. G., & Porter, R. (1989). Myosin dephosphorylation during rapid relaxation of hog carotid artery smooth muscle. The American journal of physiology, 256(2), C315-21. https://doi.org/10.1152/ajpcell.1989.256.2.C315
Driska, S P, et al. "Myosin dephosphorylation during rapid relaxation of hog carotid artery smooth muscle." The American journal of physiology vol. 256,2 (1989): C315-21. doi: https://doi.org/10.1152/ajpcell.1989.256.2.C315
Driska SP, Stein PG, Porter R. Myosin dephosphorylation during rapid relaxation of hog carotid artery smooth muscle. Am J Physiol. 1989 Feb;256(2):C315-21. doi: 10.1152/ajpcell.1989.256.2.C315. PMID: 2537571.
Copy Download .nbib Format: NLM
Share it on
Full text links
Atypon

Am J Physiol. 1989 Feb;256(2):C315-21. doi: 10.1152/ajpcell.1989.256.2.C315.

Myosin dephosphorylation during rapid relaxation of hog carotid artery smooth muscle.

The American journal of physiology

S P Driska, P G Stein, R Porter

Affiliations

  1. Department of Physiology, School of Medicine, Temple University, Philadelphia, Pennsylvania 19140.

PMID: 2537571 DOI: 10.1152/ajpcell.1989.256.2.C315

Abstract

Changes in myosin light chain phosphorylation were measured during histamine-induced rhythmic contractions of hog carotid artery smooth muscle strips. Histamine made the muscle strips contract spontaneously every 1-5 min, and this allowed measurement of the time course of phosphorylation in relation to force development under conditions where diffusion of the agonist through tissue would not complicate the interpretation of the data. In the absence of histamine, phosphorylation was low [0.12 +/- 0.04 mol P/mol of the 20,000-Da light chain (LC 20)]. Phosphorylation was slightly (but not significantly) higher in the presence of 10 microM histamine in the relaxed state between contractions (0.20 +/- 0.03 mol P/mol LC 20). In muscle strips frozen during force development, when force had reached half of its peak value, phosphorylation was 0.38 +/- 0.06 mol P/mol LC 20. The highest levels of phosphorylation (0.49 +/- 0.04 mol P/mol LC 20) were found in strips frozen at the peak of the rhythmic contractions. Strips frozen when force had declined to half of the peak force showed low levels of phosphorylation (0.17 +/- 0.07 mol P/mol LC 20), indicating that the myosin light chain phosphatase activity was quite high. Mathematical modeling of the kinase and phosphatase reactions suggested that the apparent first-order phosphatase rate constant was at least 0.08 s-1 under these conditions. To obtain a better estimate of this rate constant, a second series of phosphorylation measurements were made early in the relaxation phase of the rhythmic contractions. The highest phosphatase rate constant obtained from these measurements was 0.23 s-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Similar articles

Substances

MeSH terms

Publication Types

Grant support

LinkOut - more resources