The detection and measurement of circulating gastrin-like activity by bioassay

The development of a reliable and sensitive bioassay for gastrin in body fluids

The sensitivity and reliability of the Ghosh and Schild rat stomach preparation was improved by implantation of bulky intragastric cannulae, recirculation of the perfusate and measurement of conductivity instead of pH. With these procedures, the threshold values for gastrin I were in the range of 1-2 ng. In attempts to increase the sensitivity further it was shown that neither vagotomy nor antrectomy influenced the sensitivity of the method. The threshold values were not lowered by attempts to reduce gastrin metabolism through nephroligature or small bowel resection. Although rats fitted with portacaval shunts did raise the threshold, the limited increase in sensitivity was also achieved by selecting the rats that gave an initially high response to a test dose of gastrin thus avoiding the complicated shunt operation. The assay procedure enabled statistically valid measurements of gastrin in plasma and from tumour extracts from patients suffering from the Zollinger-Ellison Syndrome to be assayed using a 2 + 2 block design.

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.

The Bayliss-Starling lecture 1973. The gastrointestinal hormones: a review of recent advances

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