A Direct Inhibitory Effect of Botulinum Toxin Type A on Antral Circular Muscle Contractility of Guinea Pig.
10.3349/ymj.2012.53.5.968
- Author:
Jung Ho PARK
1
;
Eunjoo CHOI
;
Hyojin PARK
;
Yong Ho LEE
Author Information
1. Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
- Publication Type:Original Article ; In Vitro
- Keywords:
Botulinum toxin type A;
electrical field stimulation;
gastric antrum
- MeSH:
Acetylcholine;
Animals;
Botulinum Toxins*;
Botulinum Toxins, Type A*;
Guinea Pigs*;
Guinea*;
In Vitro Techniques;
Injections, Intramuscular;
Muscle Contraction;
Muscle, Smooth;
Pharmacologic Actions;
Pyloric Antrum
- From:Yonsei Medical Journal
2012;53(5):968-973
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: Recent studies suggest new mechanisms of Botulinum toxin (BoNT) other than inhibiting acetylcholine (ACh) release from nerve terminals. The aim of this study was to determine whether other mechanisms for BoNT exist, so that it directly inhibits smooth muscle contraction. MATERIALS AND METHODS: Guinea pig antral muscle strips were studied in vitro after 2 hours of exposure to Botulinum toxin type A (BoNT/A). Contractile responses to electric field stimulation (EFS), high K+ (60 mM) and ACh (100 microM) were evaluated 24 and 48 hours after antral intramuscular injection of BoNT/A or vehicle. RESULTS: BoNT/A inhibited muscular contraction caused by high K+ and ACh. Contractile responses to low (1 & 4 Hz) and high (8 & 20 Hz) frequency EFS of antral muscle strips 24 and 48 hours after antral intramuscular injection of BoNT/A were significantly inhibited. CONCLUSION: The ability of BoNT/A to directly inhibit antral muscular contractility suggests a new mechanism for the pharmacologic actions of BoNT-direct inhibition of muscular contraction.
