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Expression of airway contractile properties and acetylcholinesterase activity in swine.

Publication ,  Journal Article
Murphy, TM; Mitchell, RW; Blake, JS; Mack, MM; Kelly, EA; Munoz, NM; Leff, AR
Published in: J Appl Physiol (1985)
July 1989

We studied the effect of maturation on contractile properties of tracheal smooth muscle from seventeen 2-wk-old swine (2ws) and fifteen 10-wk-old swine (10ws) in situ and in vitro. The response to parasympathetic stimulation was studied in situ in isometrically fixed segments. Contraction was elicited at lower frequencies [half-maximal response to electrical stimulation (ES50) = 6.7 +/- 0.05 Hz] in 2ws than in 10ws (ES50 = 9.1 +/- 0.4 Hz; P less than 0.01). Despite substantial differences in morphometrically normalized cross-sectional area in 2ws (0.012 +/- 0.003 cm2) and 10ws (0.028 +/- 0.001 cm2; P less than 0.01), maximal active tension elicited by parasympathetic stimulation was similar (12.4 +/- 3.2 g/cm in 2ws vs. 13.3 +/- 2.3 g/cm in 10ws; P = NS). In separate in vitro studies in 25 tracheal smooth muscle strips from 10 swine, concentration-response curves generated with potassium-substituted Krebs solution (KCl) were similar in 2ws and 10ws. In 58 other strips (10 swine), maximal active force elicited with acetylcholine (ACh) in 2ws was significantly greater than for 10ws (P less than 0.001). Removal of the epithelium had no effect. However, cholinesterase inhibition with 10(-7) M physostigmine augmented the response to ACh in 10ws (P less than 0.02) but not 2ws. We demonstrate increased force generation and sensitivity to vagal stimulation in 2ws vs. 10ws, which corresponds to increased reactivity to ACh in vitro. The relative hyperresponsiveness in 2ws is specific for cholinergic response and is attenuated at least in part by maturation of the activity of acetylcholinesterase enzyme.

Duke Scholars

Published In

J Appl Physiol (1985)

DOI

ISSN

8750-7587

Publication Date

July 1989

Volume

67

Issue

1

Start / End Page

174 / 180

Location

United States

Related Subject Headings

  • Trachea
  • Swine
  • Physiology
  • Muscle, Smooth
  • Muscle Contraction
  • Male
  • Animals
  • Aging
  • Acetylcholinesterase
  • 11 Medical and Health Sciences
 

Citation

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Murphy, T. M., Mitchell, R. W., Blake, J. S., Mack, M. M., Kelly, E. A., Munoz, N. M., & Leff, A. R. (1989). Expression of airway contractile properties and acetylcholinesterase activity in swine. J Appl Physiol (1985), 67(1), 174–180. https://doi.org/10.1152/jappl.1989.67.1.174
Murphy, T. M., R. W. Mitchell, J. S. Blake, M. M. Mack, E. A. Kelly, N. M. Munoz, and A. R. Leff. “Expression of airway contractile properties and acetylcholinesterase activity in swine.J Appl Physiol (1985) 67, no. 1 (July 1989): 174–80. https://doi.org/10.1152/jappl.1989.67.1.174.
Murphy TM, Mitchell RW, Blake JS, Mack MM, Kelly EA, Munoz NM, et al. Expression of airway contractile properties and acetylcholinesterase activity in swine. J Appl Physiol (1985). 1989 Jul;67(1):174–80.
Murphy, T. M., et al. “Expression of airway contractile properties and acetylcholinesterase activity in swine.J Appl Physiol (1985), vol. 67, no. 1, July 1989, pp. 174–80. Pubmed, doi:10.1152/jappl.1989.67.1.174.
Murphy TM, Mitchell RW, Blake JS, Mack MM, Kelly EA, Munoz NM, Leff AR. Expression of airway contractile properties and acetylcholinesterase activity in swine. J Appl Physiol (1985). 1989 Jul;67(1):174–180.

Published In

J Appl Physiol (1985)

DOI

ISSN

8750-7587

Publication Date

July 1989

Volume

67

Issue

1

Start / End Page

174 / 180

Location

United States

Related Subject Headings

  • Trachea
  • Swine
  • Physiology
  • Muscle, Smooth
  • Muscle Contraction
  • Male
  • Animals
  • Aging
  • Acetylcholinesterase
  • 11 Medical and Health Sciences