Continuous monitoring of the effect of pentagastrin on gastric emptying of solid food in man.

Abstract

SUMMARY By continuous monitoring of a solid meal labelled with a radiopharmaceutical it has been possible to determine the effects of drugs on gastric emptying and motility during a single study. Predictably hyoscine delayed, and bethanechol increased, the rate of gastric emptying. Pentagastrin initially produced marked antral activity resulting in a physiological stricture and subsequent delay in the overall rate of gastric emptying. Fundal motility was unaffected though reflux from the antrum occurred.Gastric emptying tests have been used to assess physiological control mechanisms governing emptying from the intact normal stomach and to compare emptying rates in patients before and after surgery for gastroduodenal disease (Sheiner, 1975). By comparison, there are relatively few reports of studies assessing the effects of drugs on gastric emptying in the intact stomach, presumably because the established methods are relatively insensitive to intra-study manipulations. Hitherto, the actions of drugs on gastric muscle activity have usually been determined from isolated muscle preparations and from pressure and electrical studies in animals and humans.The purpose of this study was to develop a sensitive, non-invasive technique for continuously monitoring gastric emptying in the intact human stomach, so that changes in rates and patterns of emptying could be determined after drug administration. In order to explain changes in the net rate of emptying from the whole stomach, an assessment of regional muscle activity was attempted by monitoring emptying from subareas of the proximal and distal stomach.The project was developed in three parts (1) establishment of the method and its reproducibility; (2) study of drugs with known effects on the intact stomach; and (3) study of the action of the drug pentagastrin which is reported to have apparently opposing effects on motility and emptying. (Hunt and Ramsbottom, 1967;Misiewicz et al., 1967;Kelly, 1970;Dozois and Kelly, 1971;Kwong et al., 1971;Cooke et al.,1972 (Boyd et al., 1969) was then added and the meal again homogenized. This produced a meal of low fat content (6 g), 2123 J (508 calories), of pH 7 0, volume 210 ml, and total weight of 250 g. It contained a moderate protein (100 g) and carbohydrate content (28 g). Radionuclide label characteristicsThe particles of 99mTc-MAFH (size 5-50 micra) were uniformly distributed throughout the meal phase as shown by counting random samples of equal weights taken from the meal. The distribution was unaffected by centrifugation and acidification to a pH of less than 1I0. Complete aspiration of gastric contents after studies resulted in less than 3 % of the radionuclide in the supernatant. The remaining 97 % of the activity in the aspirate was uniformly distributed throughout the meal phase.Six hours after ingestion of the meal and after complete aspiration of the stomach, a gamma camera image failed to show residual radioactivity adsorbed onto the stomach wall. Serial images and counting performed over the thyroid, cardiac bloo...

Dual Effects of Rabeprazole on Solid-Phase Gastric Emptying Assessed by the ¹³C-Octanoate Breath Test

“…We think that the acid-pepsin maldigestion did not prolong the lag phase because the muffin test meal could easily be masticated. Secondly, hypergastrinemia resulting from acid suppression may suppress gastric motility [10]. Our data show that rabeprazole modestly elevated the fasting serum gastrin levels.…”

“…To date, the variable effects of omeprazole [5, 6] and lansoprazole [7, 8] on gastric motor function have been reported. It is considered that PPI-induced acid suppression with or without hypergastrinemia indirectly affects gastric motility [9, 10]. …”

The effect of beta‐adrenoceptor agonists and antagonists on gastric emptying in man.

“…Similarly, adrenergic agents increase serum gastrin levels in man (Hayes, Ardill, Kennedy, Shanks & Buchanan, 1972;Stadil & Rehfeld, 1973), and as pentagastrin is a potent inhibitor of gastric emptying in man (Hamilton et al, 1976) it is possible that /3-adrenergic receptor drugs affect gastric emptying partly by alterations in the level of gastrin. However, there is considerable debate at present as to whether gastrin plays a role in the regulation of gastric emptying under physiological conditions (Cooke, 1975 Adrenergic drugs are widely used in the management of bronchial asthma and ,3-adrenoceptor blockers such as propranolol in the treatment of angina and hypertension.…”

“…Anticholinergic drugs such as propantheline (Nimmo, Heading, Tothill & Prescott, 1973) have been shown to delay, but cholinergic drugs such as bethanechol (Hamilton, Sheiner & Quinlan, 1976) and carbachol (Tinker, Kocak & Jones, 1970) to increase the rate of gastric emptying. Drug induced alterations of gastrointestinal motility can also change drug absorption in man; e.g.…”

Pharmacological Bases of the Medical Treatment of Gastroesophageal Reflux Disease

“…If given in a suf ficient dose to maintain an increase in LESP, the cholinergic untoward effects of the drug (abdominal cramps, diarrhea, urinary fre quency and blurred vision) arc troublesome and limit its clinical usefulness. Although bethanechol has also been proposed as a drug that might improve gastric emptying [Hamilton et al, 1976;Dubois et al, 1981], definite support for this effect is not avail able Richter, 1985;Scarpignato and Zimbaro, unpubl. obs.…”