title: Effects of timepidium bromide, hyoscine-N-butylbromide and atropine on the isolated guinea pig gallbladder and sphincter of Oddi.
abstract: Effects of timepidium bromide (TB), hyoscine-N-butylbromide (HB) and atropine (Atr) were studied on the isolated guinea pig gallbladder and sphincter of Oddi. In the isolated gallbladder, the contraction induced by methacholine was competitively antagonized with TB, HB and Atr: pA2 values for TB, HB and Atr were 8.44, 7.55 and 9.11, respectively. Contraction of gallbladder after field stimulation at 5 Hz was also inhibited by TB, HB and Atr as well as by tetrodotoxin (TTX). On the other hand, TB had no significant influence on the electrically evoked (30 Hz) contraction which remained after treatment with TTX. It was estimated that the inhibitory activity of TB on the contraction of gallbladder was 1/5-1/6 that of Atr and 7 times as potent as HB. In the isolated sphincter of Oddi, TB, HB and Atr reduced the perfusion pressure increased by acetylcholine (ACh), the activity of TB being 1/4 that of Atr and 3 times of HB. The contractile responses to field stimulation (5 Hz) were also inhibited by TB, HB and Atr. The inhibitory activity of TB was 1/5 that of Atr and 12 times of HB. It was also demonstrated that TB produced no significant effect on the noradrenaline (Nor)-induced contraction and isoproterenol (Iso)-induced relaxation in the gallbladder or Nor-induced increase of the perfusion pressure in the sphincter of Oddi. It is suggested that TB acts on the gallbladder and sphincter of Oddi by virtue of its anticholinergic activity.
mesh_terms: D000109:Acetylcholine / Q000037:antagonists & inhibitors; D014670:Ampulla of Vater / Q000187:drug effects*; D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D002086:Butylscopolammonium Bromide / Q000494:pharmacology*; D003864:Depression, Chemical; D004558:Electric Stimulation; D005704:Gallbladder / Q000187:drug effects*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008688:Methacholine Compounds / Q000037:antagonists & inhibitors; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009638:Norepinephrine / Q000037:antagonists & inhibitors; D010276:Parasympatholytics / Q000494:pharmacology*; D010477:Perfusion; D010880:Piperidines / Q000494:pharmacology*; D012602:Scopolamine Derivatives / Q000494:pharmacology*; D009803:Sphincter of Oddi / Q000187:drug effects*; D013876:Thiophenes / Q000494:pharmacology*
chemical_list: D008688:Methacholine Compounds; D010276:Parasympatholytics; D010880:Piperidines; D012602:Scopolamine Derivatives; D013876:Thiophenes; D002086:Butylscopolammonium Bromide; D001285:Atropine; C001739:timepidium bromide; D000109:Acetylcholine; D009638:Norepinephrine