The effect of stimulation by meat on gastrins in pyloric antral mucosa of anaesthetized cats.

Chloralose anaesthetized cats were prepared with fundic and antral pouches. After stimulation with meat extract suspension in the antral pouches, the antral mucosae were collected, homogenized and subjected to subcellular fractionation to produce whole homogenates, debris, mitochondrial, granule and microsomal fractions and the cell supernatant. Total gastrin concentration and the quantities of gastrin components were measured in these cell fractions and compared with values obtained from a group of control animals which were not stimulated. Stimulation significantly increased the concentration of total gastrin in whole homogenates and in the cell supernatant. In whole homogenates the concentrations of gastrin components I, II, III and void volume gastrin all increased significantly after stimulation. In granules the concentration of Component III significantly increased. In microsomes the concentration of Componenet IV increased significantly. In cell supernatant the total amounts of Components III and IV increased significantly. It is concluded there was synthesis of gastrin under the experimental conditions used. The concentrations of those gastrin components which are larger than the predominant storage form (Component III) are increased and these larger components may be biosynthetic precursors. The significant increase in Component IV concentration in the cell supernatant and microsomes may suggest that Component IV is formed at least in part by antral tissue as well as by the known conversion process which occurs in cat blood.