Reflex decreases in intragastric pressure in response to cholecystokinin in rats.
The actions of intravenous sulfated cholecystokinin octapeptide (CCK-8) on intraluminal pressure in the body of the stomach were studied in urethan-anesthetized rats. There was a dose-related decrease in pressure in response to CCK-8 over the range 0.3-33 pmol. Bilateral cervical vagotomy alone reduced the response to CCK-8 and together with splanchnic section abolished it. Hexamethonium also reduced the response. Vagotomy did not change the response to CCK-8 in hexamethonium-treated rats, but celiac ganglionectomy abolished it. Guanethidine and phentolamine, but not propranolol, significantly decreased the response to CCK-8; subsequent vagotomy abolished the response. Similarly, depletion of tissue catecholamines by pretreatment with 6-OH dopamine, reserpine, or celiac ganglionectomy together with vagal section abolished the effect of CCK-8. It concluded that CCK-8 decreases mean intragastric pressure in the rat by pathways involving both vagal and splanchnic nerves. The splanchnic pathway involves an alpha-adrenergic mechanism but is hexamethonium resistant. The vagal pathway is hexamethonium sensitive and nonadrenergic. Similar pathways may mediate the effect of CCK on gastric emptying.
D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology*; D003714:Denervation; D004305:Dose-Response Relationship, Drug; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D011312:Pressure; D051381:Rats; D012018:Reflex; D012844:Sincalide / Q000494:pharmacology; D013153:Splanchnic Nerves / Q000502:physiology; D013270:Stomach / Q000187:drug effects* / Q000502:physiology; D013565:Sympatholytics / Q000494:pharmacology; D014628:Vagotomy
D006584:Hexamethonium Compounds; D013565:Sympatholytics; D018738:Hexamethonium; D002766:Cholecystokinin; D012844:Sincalide; D009638:Norepinephrine