Skip to main content
Journal cover image

Ontogenesis of myosin light chain phosphorylation in guinea pig tracheal smooth muscle.

Publication ,  Journal Article
Chitano, P; Worthington, CL; Jenkin, JA; Stephens, NL; Gyapong, S; Wang, L; Murphy, TM
Published in: Pediatr Pulmonol
February 2005

Increased airway responsiveness occurs in normal young individuals compared to adults. A maturation of airway smooth muscle (ASM) contractility is likely a mechanism of this juvenile airway hyperresponsiveness. Indeed, we showed in guinea pig tracheal smooth muscle (TSM) that maximum shortening velocity decreases dramatically after the first 3 weeks of life. Because the phosphorylation of the 20-kDa myosin light chain (MLC(20)) was shown to be a key event in ASM contractility, in the present work we sought to investigate it during ontogenesis. In three age groups (1-week-old, 3-week-old, and adult guinea pigs), we assessed the amount of MLC(20) phosphorylation achieved either in TSM crude protein homogenates exposed to Mg(2+) . ATP . CaCl(2) or in tracheal strips during electrical field stimulation (EFS). Phosphorylated and unphosphorylated MLC(20) were separated on nondenaturing 10% polyacrylamide gels, and the ratio of phosphorylation was obtained by densitometric analysis of chemiluminescent Western immunoblots. Maximum MLC(20) phosphorylation (% of total MLC(20)) in TSM tissue homogenate was, respectively, 32.6 +/- 5.7, 32.2 +/- 5.7, and 46.8 +/- 5.8 in 1-week, 3-week, and adult guinea pigs. Interestingly, in nonstimulated intact tracheal strips, we found a substantial degree of MLC(20) phosphorylation: respectively, 42.2 +/- 5.8, 36.5 +/- 7.8, and 46.4 +/- 4.7 in 1-week, 3-week, and adult guinea pigs. Maximal EFS-induced MLC(20) phosphorylation (% increase over baseline) in the 3-week age group was attained after 3 sec of EFS, and was 161.2 +/- 17.6, while in 1-week and adult guinea pigs, it was attained at 1.5 sec of EFS and was, respectively, 133.3 +/- 9.3 and 110.2 +/- 3.9 (P < 0.05). We conclude that MLC(20) phosphorylation in guinea pig intact tracheal strips correlates with ontogenetic changes in shortening velocity and changes in myosin light chain kinase content. These results further suggest that the maturation of ASM contractile properties plays a role in the greater airway responsiveness reported in children and young animals.

Duke Scholars

Published In

Pediatr Pulmonol

DOI

ISSN

8755-6863

Publication Date

February 2005

Volume

39

Issue

2

Start / End Page

108 / 116

Location

United States

Related Subject Headings

  • Trachea
  • Respiratory System
  • Phosphotransferases
  • Phosphorylation
  • Myosin-Light-Chain Phosphatase
  • Myosin Light Chains
  • Muscle, Smooth
  • Muscle Contraction
  • Male
  • Luminescent Measurements
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Chitano, P., Worthington, C. L., Jenkin, J. A., Stephens, N. L., Gyapong, S., Wang, L., & Murphy, T. M. (2005). Ontogenesis of myosin light chain phosphorylation in guinea pig tracheal smooth muscle. Pediatr Pulmonol, 39(2), 108–116. https://doi.org/10.1002/ppul.20150
Chitano, Pasquale, Charles L. Worthington, Janet A. Jenkin, Newman L. Stephens, Sylvia Gyapong, Lu Wang, and Thomas M. Murphy. “Ontogenesis of myosin light chain phosphorylation in guinea pig tracheal smooth muscle.Pediatr Pulmonol 39, no. 2 (February 2005): 108–16. https://doi.org/10.1002/ppul.20150.
Chitano P, Worthington CL, Jenkin JA, Stephens NL, Gyapong S, Wang L, et al. Ontogenesis of myosin light chain phosphorylation in guinea pig tracheal smooth muscle. Pediatr Pulmonol. 2005 Feb;39(2):108–16.
Chitano, Pasquale, et al. “Ontogenesis of myosin light chain phosphorylation in guinea pig tracheal smooth muscle.Pediatr Pulmonol, vol. 39, no. 2, Feb. 2005, pp. 108–16. Pubmed, doi:10.1002/ppul.20150.
Chitano P, Worthington CL, Jenkin JA, Stephens NL, Gyapong S, Wang L, Murphy TM. Ontogenesis of myosin light chain phosphorylation in guinea pig tracheal smooth muscle. Pediatr Pulmonol. 2005 Feb;39(2):108–116.
Journal cover image

Published In

Pediatr Pulmonol

DOI

ISSN

8755-6863

Publication Date

February 2005

Volume

39

Issue

2

Start / End Page

108 / 116

Location

United States

Related Subject Headings

  • Trachea
  • Respiratory System
  • Phosphotransferases
  • Phosphorylation
  • Myosin-Light-Chain Phosphatase
  • Myosin Light Chains
  • Muscle, Smooth
  • Muscle Contraction
  • Male
  • Luminescent Measurements