Spontaneous mechanical activities of dog trachealis muscle in vivo.

Isometric strain gauge arches attached transversely and longitudinally to cervical trachealis muscle (CTM) recorded spontaneous mechanical activities (SMA), passive constriction, and longitudinal tension in 64 dogs anesthetized with pentobarbital. Inspiratory tracheal elongation increased longitudinal tension and passively constricted CTM. Occasional overlapping of tracheal cartilages observed on initial exposure of cervical trachea appeared to be due to unprovoked persistent increases in SMA.

Contraction of dog trachealis muscle in vivo: role of alpha-adrenergic receptors.

Contraction, relaxation, and longitudinal tension were recorded by isometric strain gauge arches attached to cervical tracheal muscle (CTM) in 60 spontaneously breathing dogs anesthetized with pentobarbital. Intravenous norepinephrine (NE) (3 X 10(-9), 6 X 10(-9), 1.2 X 10(-8), and 2.