Method for the quantitation of gastric emptying time of gel test meals

Mosapride accelerates the delayed gastric emptying of high-viscosity liquids: a crossover study using continuous real-time C breath test (BreathID System)

Background/Aims

The administration of liquid nutrients to patients is often accompanied by complications such as gastroesophageal reflux. To prevent gastroesophageal reflux, high-viscosity liquid meals are used widely, however, it still remains controversial whether high-viscosity liquid meals have any effect on the rate of gastric emptying. The present study was conducted with the aim of determining whether high-viscosity liquid meals had any effect on the rate of gastric emptying and mosapride might accelerate the rate of gastric emptying of high-viscosity liquid meals.

Methods

Six healthy male volunteers underwent 3 tests at intervals of > 1 week. After fasting for > 8 hours, each subject received one of three test meals (liquid meal only, high-viscosity liquid meal [liquid meal plus pectin] only, or high-viscosity liquid meal 30 minutes after intake of mosapride). A ¹³C-acetic acid breath test was performed, which monitored the rate of gastric emptying for 4 hours. Using the Oridion Research Software (β version), breath test parameters were calculated. The study parameters were examined for all the 3 test conditions and compared using the Freidman test.

Results

Gastric emptying was significantly delayed following intake of a high-viscosity liquid meal alone as compared with a liquid meal alone; however, intake of mosapride prior to a high-viscosity liquid meal was associated with a significantly accelerated rate of gastric emptying as compared with a high-viscosity liquid meal alone.

Conclusions

This study showed that high-viscosity liquid meals delayed gastric emptying: however, mosapride recovered the delayed rate of gastric emptying by high-viscosity liquid meals.

The gastrointestinal transit profile of 14C-labelled poly(acrylic acids): an in vivo study

The gastrointestinal distribution profiles for three 14C-labelled poly(acrylic acid)s of different average molecular weights and degrees of cross-linking have been established using the rat model. Despite initial differences in transit times and retention characteristics, these structural features were found to be of little influence to the overall gastrointestinal transit of the materials under consideration. No evidence for the systemic absorption of any of the polymers could be identified.

Synthesis of radiolabeled congeners of the carbomers: (14)C-labeled poly(acrylic acid)s

A general method for the synthesis of (14)C-acrylic acid is described in detail. The material is used for the synthesis of a range of radiolabeled poly(acrylic acid)s in which the (14)C-label forms an integral part of the polymer backbone. The chemical structure of the synthesized polymers is examined in the light of spectroscopic data, molecular weight determinations, and rheological studies.

Liver phosphorylase activation during early phase of feeding behavior: a neurohumoral regulation

The mechanisms of liver glycogen depletion during the early phase of spontaneous feeding were examined in adult rats. A 40% increase in the activity of phosphorylase a, the active form of a key glycogenolytic enzyme, was detected 5 min after the onset of feeding, with a concomitant decrease of glycogen in the liver after 5 and 15 min. Within 60 min after the onset of feeding, the enzyme activity returned to the basal level and the glycogen content was restored. These metabolic responses were impaired by hepatic sympathetic denervation or by bilateral adrenodemedullation. It was concluded that the onset of meals may evoke an arousal of the sympathoadrenal system including the hepatic innervation, and that activation of this system is important in stimulating liver phosphorylase activity and glycogenolysis during the early phase of spontaneous feeding.

Adsorption of inorganic and organic ions to polycarbophil as a means of sustained-release dosage formulation

The adsorption and desorption of drugs and inorganic ions to and from polycarbophil (PC), a polymer, were investigated to determine if PC would be a suitable carrier for sustained-release dosage formulations. Both in vitro and in vivo experiments with a polycarbophil-atropine sulfate complex demonstrated the gradual-release properties of this system. Adsorbed Cr3+ ions, like atropine, are released slowly. In contrast, 51CrO4(2-) ions are predominantly bound in an irreversible manner. A third group of drugs minimally adsorbed to PC under the conditions studied. We conclude that PC under both in vitro and in vivo conditions is able to bind certain ions and drugs and then release them over a period of time in a predictable and repeatable manner.

The effect of polycarbophil on the gastric emptying of pellets

The influence of the putative bioadhesive, polycarbophil, on the gastric emptying of a pellet formulation, has been investigated in three fasted subjects. The pellets were radiolabelled with technetium-99m. Gastric emptying was measured using the technique of gamma scintigraphy. The pellets emptied from the stomach rapidly and in an exponential manner. Polycarbophil did not retard the gastric emptying of the pellets.

Effects of laxative and nonlaxative hydrophilic polymers on canine small intestinal motor activity

Bulk-forming laxatives increase fecal volume and elicit aborally directed colonic motility patterns. Recently, it was demonstrated that test meals of the bulk-laxative fibers (cellulose and bran) elicited organized jejunal motor activity while nonlaxative fiber meals (guar) elicited unorganized jejunal motor activity. However, whether bulk-forming laxatives, as a class of compounds, differentially affect small intestinal motility has not been studied. Therefore, a study was made of the effects of the bulk laxatives psyllium and polycarbophil and the nonlaxative pectin on canine jejunal motor activity. Psyllium and pectin are examples of dietary fiber, while polycarbophil is a synthetic polymer. Pectin and psyllium test meals presented as viscous gels. In contrast, polycarbophil meals presented as a combination of discrete particles plus meal water. After each meal, measurements were made of the jejunal motility index, the time of reappearance of interdigestive burst activity, and overall motility patterns. Pectin and psyllium meals increased in viscosity as meal fiber content increased. As meal content and hence viscosity increased, both the laxative (psyllium) and nonlaxative (pectin) fiber meals elicited increasing jejunal motor activity and delays in the reappearance of the burst interval. For both fiber types, motor activity presented as randomly appearing contractions. In contrast, meals of the laxative polycarbophil elicited no more motor activity than the saline control meal. However, this control-level amount of activity presented as propagated clusters of contractions, ie, the "laxative-induced pattern." Polycarbophil did not delay the reappearance of burst activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Canine gastric emptying of polycarbophil: an indigestible, particulate substance

We tested whether indigestible solids could empty from the canine stomach independently of gastric burst motor activity. Test meals contained polycarbophil, an indigestible particulate (1-3 mm diameter) substance. Test meals were slurries of 30 or 90 g of radiolabeled polycarbophil particles in saline. Meals were administered via an oral gastric tube. After 4 h, the stomach was drained via a gastric cannula, and the percentage of meal that had emptied into the duodenum was calculated. Antroduodenal motor responses to the meals were monitored with strain-gage force transducers. The motor responses to polycarbophil meals were compared with those after canned food and saline meals. Fifty percent of the 90-g polycarbophil meal emptied by 4 h; this occurred independently of gastric burst motor activity. Both polycarbophil and canned food elicited similar indexed motor responses and both delayed the postprandial reappearance of gastric burst motor activity. We conclude that small indigestible particles can stimulate fed state-like motility and empty from the stomach independently of gastric burst activity.