Control of gastric emptying in the pig: influence of cholecystokinin, somatostatin and prokinetic agents

Abstract

SUMMARYThe influence of systemic arterial infusions of cholecystokinin octapeptide (CCK8) and somatostatin, and injections of cisapride, metoclopramide and atropine on gastric emptying were studied in eight pigs. Gastric emptying of dry matter (DM) and liquids (Cr-EDTA as marker) was measured, in pigs fitted with a gastric cannula, by evacuation of gastnc contents either immediately after the pigs had finished feeding, or 3 h after being fed a meal containing 1200 g of a finely ground barley diet mixed with 2-4 1 water. Gastric emptying of DM and liquids during the feeding period was not significantly altered by cisapride (0.15 and 0-3 mg kg-'-1), metoclopramide (0-2 mg kg-'), CCK8 (250 ng kg-' h-1) or somatostatin (1.8 and 4-5 jug kg-1 h-1); atropine (0.06 mg kg-') slowed emptying of DM (by 53 + 6 %; P < 0 001) and of liquids (by 51 + 7 %, P < 0.01). In contrast, the amount of DM emptied within 3 h of feeding was significantly reduced with CCK8 (250 ng kg-1 h-1; by 14 + 3 %, P < 0.001) and with somatostatin (1 8 jug kg-1 h-1; by 10± 4%; P < 0001). There was no increase in emptying of DM or liquids with cisapride or metoclopramide; indeed, there was actually a reduction in liquid emptying (by 13 + 6%; P < 0 05) with cisapride (0 3 mg kg-'). Gastric emptying in the pig is therefore resistant both to stimulation by prokinetic agents, and to inhibition by some putative neurohormonal modulators at the doses used; gastric emptying during feeding is even more resistant to alteration than is emptying between meals. It is concluded that in the pig, neither CCK nor somatostatin are involved in regulation of gastric emptying during the feeding period, but that both may play a minor role in regulation of emptying between meals. The low sensitivity to CCK may be a factor in the rapid gastric emptying of the pig.

Effect of cisapride on myoelectrical activity of the antrum pylori in the conscious miniature pig

“…In young pigs (30±35 kg) gastric emptying of dry matter and liquids, using Cr-EDTA as a marker, is not significantly changed by intra-aortic injection of cisapride (Gregory et al, 1995). The authors suggest that one possible cause of the lack of a stimulatory effect is the very rapid gastric emptying rate normal in pigs.…”

“…In this species and in cats cisapride is clinically useful in the management of gastric stasis, gastrooesophageal reflux and chronic constipation due to megacolon (Dowling, 1995). In pigs, however, gastric emptying is resistant to cisapride (Gregory et al, 1995). The aim of the present study was to examine the effect of intravenous (i.v.)…”

“…The authors suggest that one possible cause of the lack of a stimulatory effect is the very rapid gastric emptying rate normal in pigs. It must be mentioned that the study of Gregory et al (1995) was performed on conventional pigs (Large White6 Landrace) and that cisapride was administered into the abdominal aorta, at a dosage of 0.15 and 0.30 mg/kg. In our experiments on miniature pigs cisapride was administered i.v.…”

“…at higher doses of 0.5 and 1 mg/kg. Gregory et al (1995) examined the influence of the prokinetic drug on gastric emptying, whereas in the present study its effect on antral electrical activity was evaluated. Differences between breeds or strains of animals, injection route, doses and studied parameter, may therefore account for the disagreement between the results of both porcine studies.…”

Effect of Cisapride on Myoelectrical Activity of the Gastrointestinal Tract in the Conscious Miniature Pig

“…rat, guinea pig, dog and man (SCHUURKES et al, 1984(SCHUURKES et al, , 1985STACHER et al, 1986;GULLIKSON et al, 1991;BRIEJER et al, 1995). To the authors' knowledge, the effect of these benzamides in the porcine species has only been examined in one study (GREGORY et al, 1995). Contrary to the gastroprokinetic effect in other species, these drugs do not accelerate gastric emptying in the pig (GREGORY et al, 1995).…”