Characterization of [3H]pentagastrin binding in guinea pig gastric glands--an alternative convenient ligand for receptor binding assay.
The binding of [3H]pentagastrin to guinea pig gastric glands was specific, saturable and of high affinity (Kd = 5 nM). The relative order of potencies for gastrin and CCK analogs in displacing [3H]pentagastrin binding correlated well with those obtained using [125I]gastrin and their reported biological potencies for stimulating acid secretion. Nonselective CCK/gastrin antagonists including carbobenzoxy-CCK (26-32), proglumide and benzotript, but not the selective peripheral CCK antagonist, asperlicin, inhibited specific [3H]pentagastrin binding. The results indicate that [3H]pentagastrin labels physiologically relevant gastrin receptors in guinea pig gastric glands.
D000818:Animals; D001667:Binding, Competitive; D005753:Gastric Mucosa / Q000378:metabolism*; D005755:Gastrins / Q000037:antagonists & inhibitors; D006168:Guinea Pigs; D007700:Kinetics; D010418:Pentagastrin / Q000378:metabolism*; D011869:Radioligand Assay; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011949:Receptors, Cholecystokinin; D013329:Structure-Activity Relationship
D005755:Gastrins; D011956:Receptors, Cell Surface; D011949:Receptors, Cholecystokinin; D010418:Pentagastrin