Effect of neurotensin on the canine gallbladder motility: in vivo and in vitro experiments.
Neurotensin (NT) (10(-8)-10(-6)) exerted a dose-dependent increase in the tone and release of [3H]ACh in the guinea-pig gallbladder muscle strips but was inefficient in the canine gallbladder muscle strips. However, in conscious dogs NT (2.5-20 ng/kg intravenously (i.v.)) dose-dependently increased the gallbladder pressure. Similar was the effect of CCK8 (1-10 ng/kg i.v.) and carbachol (0.5-2 micrograms/kg i.v.). The NT- or CCK8-induced gallbladder pressure was inhibited by atropine (10-50 micrograms/kg i.v.) or hexamethonium (0.5-3 mg/kg i.v.). Somatostatin (1-2 micrograms/kg i.v.) or VIP (0.5-1 microgram/kg i.v.) also reduced or even abolished the NT- or CCK8-induced gallbladder pressure. The NT-induced increase of the tone of guinea-pig gallbladder preparations was accompanied by an increase of [3H]ACh release, suggesting the involvement of cholinergic innervation.
Milenov
K
K
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Vassileva
M
M
Marinova
D
D
Kalfin
R
R
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D004285:Dogs; D005704:Gallbladder / Q000187:drug effects / Q000502:physiology*; D006168:Guinea Pigs; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009496:Neurotensin / Q000008:administration & dosage / Q000494:pharmacology*; D011312:Pressure; D012844:Sincalide / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D014316:Tritium
D006584:Hexamethonium Compounds; D014316:Tritium; D009496:Neurotensin; D018738:Hexamethonium; D013779:Tetrodotoxin; D001285:Atropine; D002217:Carbachol; D012844:Sincalide; D000109:Acetylcholine