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Regional differences in contraction produced by methacholine and electric field stimulation (EFS) and in relaxation produced by isoproterenol, prostaglandin E2 and verapamil were studied in isolated canine airway smooth muscle in vitro. Low-frequency EFS (3 Hz, 0.5 msec, 50 V) contracted thoracic trachealis to 43% of maximal EFS response, whereas cervical trachealis contracted to only 14% of maximum. EFS at 10 Hz produced 75% of the maximal response in both regions of the trachea. These EFS responses were abolished by 0.1 microM tetrodotoxin and 1.0 microM atropine. Contraction produced by EFS was also matched in each tissue by contraction with methacholine. The concentrations of methacholine that matched EFS at 10 Hz were 52 +/- 7, 378 +/- 84 and 66 +/- 11 nM for cervical and thoracic trachealis and lobar bronchi, respectively. Both EFS and matched methacholine contractions of cervical trachealis and lobar bronchi were completely relaxed by isoproterenol, whereas thoracic trachealis relaxed maximally to only 60% of induced tone. When verapamil was used to relax EFS and matched methacholine contractions, cervical trachealis was completely relaxed whereas thoracic trachealis relaxed to 15% of induced tone. Although there was a regional difference in the relaxant potency of isoproterenol and, to some extent, verapamil, there was no difference in isoproterenol or verapamil EC50 values for EFS vs. matched methacholine contractions within each region. In contrast, EFS contractions of thoracic trachealis were more sensitive to prostaglandin E2-induced relaxation than were matched methacholine contractions. These data demonstrate marked differences in cholinergic and beta adrenergic receptor-mediated responses between regions of the tracheobronchial tree.(ABSTRACT TRUNCATED AT 250 WORDS)
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
July 1992,
The Journal of pharmacology and experimental therapeutics,
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
July 2007,
Canadian journal of physiology and pharmacology,
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
January 1985,
Life sciences,
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
October 1987,
Journal of applied physiology (Bethesda, Md. : 1985),
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
June 2015,
The Journal of endocrinology,
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
January 1981,
Lung,
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
April 1993,
Prostaglandins,
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
June 1990,
The American journal of physiology,
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
March 1989,
Journal of applied physiology (Bethesda, Md. : 1985),
D H Moore, and
P W Abel, and
G A Rinard, and
A M Puckett, and
J B Walter
August 1995,
Thorax,
