PROGASTRIN AND ITS PRODUCTS IN THE CEREBELLUM

So far the only CNS neurons found to express gastrin have been hypothalamo-hypophyseal. Using a library of radioiommunoassays specific for different sequences of porcine progastrin in combination with chromatography and enzyme cleavages, 21 or 24 porcine cerebelli was now found to contain progastrin or its products. Sixteen cerebelli processed progastrin via glycine-extended intermediates to bioactive, carboxyamidated gastrin-17 and -34, half of the gastrins being tyrosine O-sulfated. The mean concentration of carboxyamidated gastrins was 0.8 pmol/g tissue (range < 0.1-2.1 pmol/g), of glycine-extended intermediates 0.1 pmol/g (range < 0.1-0.3 pmol/g) and of progastrin 0.4 pmol/g (range < 0.1-1.0 pmol/g). The results show that the gastrin gene is expressed in more than a single region of the brain.