Abstract
Effects of GABA A- and GABA B-receptor agonists and antagonists on the intestinal myoelectric activity were investigated after intracerebroventricular (i.c.v.) and intravenous (i.v.) administration to conscious ewes, chronically fitted with intraparietal electrodes in the duodenum and jejunum and a cannula in the left cerebral ventricle. Muscimol (i.v.: 25 μg/kg; but not i.c.v.: 0.1 μg/kg) and baclofen (i.v.: 500 μg/kg; i.c.v.: 1 μg/kg) decreased duration of the migrating myoelectric complex along the duodeno-jejunum by shortening the period of the irregular spiking activity, while leaving unaffected that of the regular spiking activity. Neither bicuculline (i.v.: 50 μg/kg and i.c.v.: 0.4 μg/kg) nor phaclofen (i.c.v.: 80 μg/kg) had any significant effect when given alone , but i.v. pretreatment with the former completely prevented the action of i.v. muscimol, and i.c.v. pretreatment with the latter abolished the effects of i.c.v. baclofen, while greatly reducing those of its i.v. administration. It is concluded that activation of peripheral GABA A- and central and probably peripheral GABA B-receptors inhibits duodeno-jejunal propelling activity, emphasizing indirectly the mixing contractions.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call