title: Two types of 'slow waves' in intestinal smooth muscle of cat.
abstract: 1. Smooth muscle from cat small intestine shows two types of spontaneous slow electrical waves in the frequency range of 10-15 min-1. One type of slow wave is a ouabain-sensitive, atropine-insensitive spontaneous oscillation. The other type of wave can be induced by acetylcholine (ACh), is blocked by atropine, and is not blocked by ouabain. 2. Ouabain-sensitive slow waves rise directly from the baseline, are near sinusoidal and may or may not have spikes. ACh-induced waves have pre-potentials, are usually topped by spikes and show after-hyperpolarization. 3. The two types of rhythmic wave differ in ionic and metabolic requirements and drug sensitivity. Ouabain-sensitive waves occur only in intestinal muscle attached to a boundary layer containing interstitial cells; ACh-induced waves can occur in strips of muscle lacking boundary cells. 4. Na+ pump inhibitors ouabain, cold and K+-free solution, reduce amplitude but not frequency of ouabain-sensitive slow waves. 5. The ACh-induced waves require higher extracellular concentrations of Na+ and Ca2+ and can occur in preparations in Li+-Krebs solution; the ouabain-sensitive rhythm persists in lower concentrations of Na+ and Ca2+ and is not supported by Li+. The ouabain-sensitive waves are more sensitive to cyanide and less sensitive to cooling than the ACh-induced waves. 6. Guinea-pig intestine shows only one type of rhythmic wave, which is atropine sensitive and resembles in shape the ACh-induced wave of other species. Ouabain increases the frequency of the guinea-pig rhythm. 7. It is concluded that intestinal muscle of most mammals, but not of guinea-pig, is capable of two types of slow electrical rhythms.
authors.affiliation: Department of Physiology and Biophysics, University of Illinois, Urbana-Champaign 61801.
authors.forename: V
authors.initials: V
authors.lastname: Dahms
authors.forename: C L
authors.initials: CL
authors.lastname: Prosser
authors.forename: N
authors.initials: N
authors.lastname: Suzuki
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002415:Cats; D005260:Female; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000502:physiology*; D008094:Lithium / Q000494:pharmacology; D008297:Male; D009130:Muscle, Smooth / Q000502:physiology*; D009712:Nucleotides, Cyclic / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D012964:Sodium / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
chemical_list: D009712:Nucleotides, Cyclic; D010726:Phosphodiesterase Inhibitors; D010042:Ouabain; D001285:Atropine; D008094:Lithium; D012964:Sodium; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium