Electric and motor activity of innervated and vagally denervated feline esophagus
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Motor and electric activities of the feline esophagus were detected before and after vagotomy by use of intraluminal pressure detectors and chronically implanted platinum electrodes. These were placed in the midesophagus (E1), at the three-quarter point (E2) and in the lower 2 cm (E3). Both inner and outer layers of muscle were skeletal at E1 and smooth at E3, whereas at E2 the outer layer was predominantly skeletal and the inner predominantly smooth. Before vagotomy, contractions of the skeletal muscle fibers of the midesophagus were associated with pressure changes and action potentials of lesser amplitude, briefer duration and faster propagation than those of the smooth muscle fibers of the lower esophagus. The frequency of the skeletal muscle action potentials was greater than 25 cycles per second (cps), and that of the smooth muscle action potentials was less than 25 cps. The first recorded event during peristalsis was orad movement of the electrodes due to contraction of longitudinal fibers. After vagotomy, action potentials occurred with nearly every stimulation, but the incidence of intraluminal pressure increases was reduced. Repetitive responses were common. Action potentials with frequencies faster than 25 cps were eliminated in the lower quarter of the esophagus were orad movement of electrodes was also abolished owing to paralysis of longitudinal muscle fibers. The incidence of peristalsis was reduced during the first month after vagotomy to between 33 and 44% of responses, but thereafter its occurrence improved to 40 to 80% of responses. The predominant electromotor features of the period after vagotomy were persistent weakness, incoordination and repetitive responses in the lower esophagus, which prevented normal emptying of the organ.
KeywordsOuter Layer Longitudinal Muscle Skeletal Muscle Fiber Intraluminal Pressure Lower Esophagus
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- 4.Miller ME: Guide to the Dissection of the Dog. Third edition. Ann Arbor, Edwards Brothers, Inc, 1952Google Scholar
- 5.Mann CV, Shorter RG: Structure of the canine esophagus and its sphincters. J Surg Res 4:160–163, 1964Google Scholar
- 8.Zeller W, Burget GE: A study of the cardia. Am J Dig Dis 4:113–120, 1937Google Scholar
- 11.Lambert EH: Strain gauges: resistance wire, Medical Physics (Vol 2). Edited by O Glasser. Chicago, Year Book Medical Publishers, Inc, 1950, pp 1090–1098Google Scholar
- 12.Code CF, Schlegel JF: Motor action of the esophagus and its sphincters, Handbook of Physiology (Vol 4). Section 6: Alimentary Canal. Edited by CF Code, W Heidel. Washington DC, American Physiological Society, 1968, pp 1821–1839Google Scholar
- 15.Roman C, Orengo M, Tieffenbach L: Étude électromyographique du muscle lisse oesophagien chez le chat. J Physiol (Paris) 61:Suppl 2:390, 1969Google Scholar
- 16.Gonella J: Étude électrophysiologique de la motricite intestinale. Thése, Marseille, 1967Google Scholar
- 18.Cannon WB: Oesophageal peristalsis after bilateral vagotomy. Am J Physiol 19:436–444, 1907Google Scholar