Radioligand binding assay of gastrin receptor(GR) was established to determine GR content and Kd of gastric cancer and mucosa in specimens of 34 patients. Both of Gs-5 and [len15]Gs-17
as unlabelled ligand
can inhibit the binding of 125I-(leu15)Gs-17to the membrane
and the inhibiting effect of Gs-5 is slightly stronger than that of (len15)Gs-17.Mixed cellulose acetate filters have better effect to separate bound 125I (leu15)Gs-17 from free 125I- (len15)Gs-17 than glass fibre filters (Hongguan 999999).The GR of gastric cancer correlates with that of mucosa in the same region of 34patients.