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Biomedical subjects

R F Harvey

Publications and source records attributed to R F Harvey.

At least 91 records · Page 5Linked to original sources
PubMed1976

Effect of metiamide on basal and stimulated serum cholecystokinin levels in duodenal ulcer patients.

Serum cholecystokinin (CCK) levels were measured in 10 patients with chronic duodenal ulcers, fasting and at intervals after two standard tests meals (300 ml of 40 mmol/1 phenylalanine solution), one given before and one during H2-receptor blockade with metiamide (200 mg four times a day). Fasting serum CCK levels were lower in all patients during treatment with metiamide (the mean level falling from 306-0 +/- 102-0 (SEM) to 82-1 +/- 23-6 pg/ml after treatment (p less than 0-01)). In contrast, peak serum CCK levels after the meal were not significantly different (7400 +/- 1141 pg/ml before treatment and 7569 +/- 1293 pg/ml on metiamide). We conclude that in duodenal ulcer patients CCK secretion under basal condtions may be in part dependent on stimulation of the small intestinal mucosa by gastric acid, but that, after an amino acid meal, gastric acid secretion is less important in determining the amount of CCK released.

Cholecystokinin↗
PubMed1975

Relationship between changes in plasma gastrin and lower oesophageal sphincter pressure after meals.

Changes in plasma gastrin and lower oesophageal sphincter pressure were measured in 20 subjects after a standard protein meal. Significant increases in both gastrin and sphincter pressure were seen. Peak gastrin response occurred an average of 19-5 minutes and peak lower oesophageal sphincter response 40-0 minutes after the meal. Both gastrin and sphincter pressure showed a wide spectrum of response. In 5 subjects there was no appreciable rise (less than 5 pg/ml) in plasma gastrin after the meal, and 3 of these had symptoms of oesophageal reflux. In this group there was only a small but nervertheless significant rise in lower oesophageal sphincter pressure (mean pressure rise 18-0 per cent of fasting value, p less than 0.05). Greater increases in sphincter pressure (mean rise 54-2 per cent, p less than 0.005) were seen in subjects with a moderate (up to 50 pg/ml) rise in plasma gastrin, and those with the most marked gastrin response (less than 50 pg/ml) showed the greatest rise in pressure (mean rise 80-3 per cent, p less than 0.0025). These results suggest that endogenous plasma gastrin is the main stimulus to the rise in lower oesophageal sphincter pressure after food. Subjects with a poor gastrin response to the meal have only a small increase in sphincter pressure and as a result may be more liable to develop gastro-oesophageal reflux.

Dietary Proteins↗
PubMed1975

Relationship between changes of serum cholecystokinin-pancreozymin and serum insulin after different stimuli.

The relationship between changes of serum immuno-reactive cholecystokinin-pancreozymin (CCK-PZ) and serum immuno-reactive insulin has been studied after various stimuli. The oral administration of 5 percent glucose or magnesium sulphate and the intra-duodenal administration of olive oil were all followed by a rise of serum CCK-PZ. The serum insulin rose after 5 percent glucose and also showed a small but insignificant rise with olive oil. There was, however, no change of serum insulin after the ingestion of magnesium sulphate suggesting that CCK-PZ in isolation does not stimulate insulin release.

Adult↗
PubMed1975

Hormonal control of gastrointestinal motility.

The motor responses of the gastrointestinal tract to a meal are tuned to provide the optimal conditions for digestion and absorption of food. Hormones released from the mucosa of the intestinal tract play an important role in regulating and integrating the various motor events which occur. Complex feedbacks, both nervous and humoral, control the release of intestinal hormones and also modify their actions. Preliminary studies suggest that abnormalities in the secretion or action of various gastrointestinal hormones may play an important role in the production of motor disorders of the gastrointestinal tract.

Cholecystokinin↗
PubMed1975

The effect of wheat bran on intestinal transit.

In 18 students and two members of staff at a boys' boarding school, the time taken to pass 20 out of 25 radiopaque pellets varied from one to seven days while the subjects were eating a normal English diet. After the additon of bran, about 20 g daily, to this diet transit time fell from 2-75 plus or minus 1-6 to 2-0 plus or minus 0-9 days (P smaller than 0-025). Transit became faster in all nine subjects who had an initial time of three days or more, and in three of seven with an initial time of two days, but became slower in all four boys with an initial one-day transit. Frequency of defaecation correlated poorly with transit time (a once daily bowel action being found with transit times ranging from one to four days), and did not increase significantly with bran. In 10 additional adults with slow initial transit (three or four days) the effect of bran was compared with that of an equal volume of ground oatflakes in a double-blind crossover trial. Bran caused a significant acceleration of transit, wherease oatmeal had no effect. These studies confirm that bran accelerates slow intestinal transit and show that this is not simply a psychological effect. Bran may also slow down fast transit.

Adolescent↗
PubMed1974

Radioimmunoassay of cholecystokinin-pancreozymin.

A sensitive and specific radioimmunoassay for cholecystokinin-pancreozymin (CCK-PZ) has been developed, using rabbit antisera to crude porcine hormone. Highly purified porcine CCK-PZ, labelled with (131)I, and repurified by column chromatography on Sephadex G15, was used as tracer. Separation of free from antibody-bound labelled CCK-PZ was carried out using charcoal, ion-exchange resin, or a double antibody procedure. Non-specific interference with the assay system by serum factors was abolished (as judged by in-vitro and in-vivo recovery studies) by boiling and diluting the serum samples before assay. Ninety-nine per cent pure porcine CCK-PZ (standard), commercial CCK-PZ preparations, caerulein, the C-terminal 8- and 12-amino acid fragments of the CCK-PZ molecule, and endogenous human CCK-PZ all cross reacted in the assay system and showed parallel inhibition curves. No significant cross reaction was found with gastrin, secretin, glucagon, or insulin. The sensitivity of the assay is approximately 5 pg per ml of test solution, which proved adequate for measuring physiological levels of CCK-PZ in peripheral blood in man.The mean immunoreactive CCK-PZ concentration in 50 fasting normal subjects was 60.4 pg per ml. The distribution of individual values was skewed, however, so that the median was much lower (30 pg per ml). Older subjects had higher fasting levels of CCK-PZ than were found in young adults.

Adult↗