Abstract
1 Mechanical activity was recorded from one segment of guinea-pig trachealis muscle while intracellular electrical activity was simultaneously recorded from a contiguous segment. When the tissue was stimulated by 1-32 mmol/l tetraethylammonium (TEA) it became clear that the electrical and mechanical records were not directly correlated. 2 Dual recording of mechanical activity from two contiguous segments of trachealis revealed that one tissue segment could exhibit phasic activity whilst the other could exhibit tonic activity, despite exposure to the same concentration of TEA. 3 Histological studies revealed that the trachealis muscle was organized into bundles largely separated from one another by spaces filled with connective tissue. However, muscle bundles branched and formed anastomotic connections with near neighbours. 4 It is concluded that the cell to cell spread of muscle excitation is very poor along the longitudinal axis of the trachea. The trachealis muscle as a whole does not function as a single unit. Rather it may represent a series of effector units each comprising a small number of smooth muscle bundles.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Hoyes A. D., Barber P. Innervation of the trachealis muscle in the guinea-pig: a quantitative ultrastructural study. J Anat. 1980 Jun;130(Pt 4):789–800. [PMC free article] [PubMed] [Google Scholar]
- Jones T. R., Kannan M. S., Daniel E. E. Ultrastructural study of guinea pig tracheal smooth muscle and its innervation. Can J Physiol Pharmacol. 1980 Aug;58(8):974–983. doi: 10.1139/y80-148. [DOI] [PubMed] [Google Scholar]
- Kroeger E. A., Stephens N. L. Effect of tetraethylammonium on tonic airway smooth muscle: initiation of phasic electrical activity. Am J Physiol. 1975 Feb;228(2):633–636. doi: 10.1152/ajplegacy.1975.228.2.633. [DOI] [PubMed] [Google Scholar]
- Small R. C. Electrical slow waves and tone of guinea-pig isolated trachealis muscle: effects of drugs and temperature changes. Br J Pharmacol. 1982 Sep;77(1):45–54. doi: 10.1111/j.1476-5381.1982.tb09267.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Small R. C., Weston A. H. Simultaneous long-term recording of the mechanical and intracellular electrical activity of smooth muscles. J Pharmacol Methods. 1980 Jan;3(1):33–38. doi: 10.1016/0160-5402(80)90062-5. [DOI] [PubMed] [Google Scholar]