Spontaneous electrical activity of interstitial cells of Cajal isolated from canine proximal colon

• Published in: Proceedings of the National Academy of Sciences - PNAS 1989-09, Vol.86 (18), p.7280-7284
• Main Authors: Langton, P. (University of Nevada School of Medicine, Reno, NV), Ward, S.M, Carl, A, Norell, M.A, Sanders, K.M
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Calcium - pharmacology; Calcium Channels - physiology; Canines; Cell physiology; CELL STRUCTURE; CELLS; CELLULE; CELULAS; CHIEN; Colon - cytology; Colon - physiology; Colon - ultrastructure; Depolarization; DOGS; Electric Conductivity; Electric current; Electric potential; electrical activity; ELECTRICAL PROPERTIES; ELECTRICIDAD; ELECTRICITE; ELECTRICITY; electrophysiology; ENVIRONMENT; ENVIRONNEMENT; ESTRUCTURA CELULAR; Female; FONCTION PHYSIOLOGIQUE; FUNCION FISIOLOGICA; Fundamental and applied biological sciences. Psychology; GASTROINTESTINAL MOTILITY; In Vitro Techniques; Interstitial cells; Interstitial cells of Cajal; INTESTIN; INTESTINES; INTESTINOS; Male; MEDIO AMBIENTE; Membrane Potentials; Microscopy, Electron; Molecular and cellular biology; MOTRICITE GASTROINTESTINALE; MOVILIDAD GASTROINTESTINAL; MUSCLE; Muscle contraction; Muscle, Smooth - cytology; Muscle, Smooth - physiology; Muscle, Smooth - ultrastructure; MUSCLES; MUSCULOS; Neurons; PERRO; PHYSIOLOGICAL FUNCTIONS; Pipettes; Potassium Channels - drug effects; Potassium Channels - physiology; PROPIEDADES ELECTRICAS; PROPRIETE ELECTRIQUE; Smooth muscle myocytes; STRUCTURE CELLULAIRE
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.86.18.7280

Interstitial cells of Cajal (ICC) have been suggested as pacemaker cells in the gastrointestinal tract. A method was developed to isolate ICC from the slow-wave pacemaker region of the canine proximal colon. These cells were identified under phase-contrast microscopy, and their identity was verified by comparing their ultrastructure with the morphology of ICC in situ. Patch-clamp experiments demonstrated that these cells are excitable; voltage-dependent inward and outward currents were elicited by depolarization. Inward current transients were identified as calcium currents. A portion of the outward current appears to be due to Ca2+-activated K channels commonly expressed in these cells. ICC were also spontaneously active, generating electrical depolarizations similar in waveform to slow-wave events of intact colonic muscles. These findings are consistent with the hypothesis that ICC initiate rhythmicity in the colon.