Radioimmunoassay for motilin.

A specific radioimmunoassay for motilin has been developed with the use of antisera to porcine motilin raised in guinea pigs. Highly purified 125-I-motilin was used as the tracer and the sensitivity range was 10 to 320 pg. No cross-reactivity was demonstrated with gastric inhibitory polypeptide, secretin, glucagon, gastrin, cholecystokinin-pancreozymin, or vasoactive intestinal peptide. In dogs with denervated pouches of the fundus of the stomach and Mann-Bollman fistulae, duodenal alkalinization resulted in an increase in gastric motor activity in the fundic pouch with a corresponding increase in serum motilin.