title: The ACB technique: a biomagentic tool for monitoring gastrointestinal contraction directly from smooth muscle in dogs.
abstract: The aim of this paper was to verify whether AC biosusceptometry (ACB) is suitable for monitoring gastrointestinal (GI) contraction directly from smooth muscle in dogs, comparing with electrical recordings simultaneously. All experiments were performed in dogs with magnetic markers implanted under the serosa of the right colon and distal stomach, and their movements were recorded by ACB. Monopolar electrodes were implanted close to the magnetic markers and their electric potentials were recorded by electromyography (EMG). The effects of neostigmine, hyoscine butylbromide and meal on gastric and colonic parameters were studied. The ACB signal from the distal stomach was very similar to EMG; in the colonic recordings, however, within the same low-frequency band, ACB and EMG signals were characterized by simultaneity or a widely changeable frequency profile with time. ACB recordings were capable of demonstrating the changes in gastric and colonic motility determined by pharmacological interventions as well as by feeding. Our results reinforce the importance of evaluating the mechanical and electrical components of motility and show a temporal association between them. ACB and EMG are complementary for studying motility, with special emphasis on the colon. ACB offers an accurate method for monitoring in vivo GI motility.
authors.affiliation: Departamento de Física e Biofísica, Instituto de Biofísica, Laboratório de Biomagnetismo, São Paulo State University, CXP 510, CEP 18618-000, Botucatu, São Paulo, Brazil.
authors.forename: Madileine F
authors.initials: MF
authors.lastname: Américo
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Oliveira
authors.forename: Luciana A
authors.initials: LA
authors.lastname: Corá
authors.forename: Rozemeire G
authors.initials: RG
authors.lastname: Marques
authors.forename: Fernando G
authors.initials: FG
authors.lastname: Romeiro
authors.forename: Uilian
authors.initials: U
authors.lastname: Andreis
authors.forename: José Ricardo A
authors.initials: JR
authors.lastname: Miranda
mesh_terms: D000818:Animals; D002086:Butylscopolammonium Bromide / Q000494:pharmacology; D003106:Colon / Q000187:drug effects / Q000502:physiology*; D004285:Dogs; D004435:Eating / Q000502:physiology; D004567:Electrodes, Implanted; D004574:Electromagnetic Fields; D004576:Electromyography; D005260:Female; D005766:Gastrointestinal Contents; D008991:Monitoring, Physiologic / Q000379:methods*; D009068:Movement / Q000187:drug effects / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D009388:Neostigmine / Q000494:pharmacology; D010277:Parasympathomimetics / Q000494:pharmacology; D012704:Serous Membrane; D013270:Stomach / Q000187:drug effects / Q000502:physiology*
chemical_list: D010277:Parasympathomimetics; D002086:Butylscopolammonium Bromide; D009388:Neostigmine