EFFECTS OF Z-300, A NEW HISTAMINE H-2-RECEPTOR ANTAGONIST, ON MUCIN BIOSYNTHESIS IN RAT GASTRIC-MUCOSA

We examined the effects of Z-300 phenoxy]propyl]-2-(2-hydroxyethyl-1-t hio)acetamido . 2-(4-hydroxy benzoyl)benzoate), a newly-synthesized se lective histamine H-2-receptor antagonist, on mucin in rat gastric muc osa. Deep corpus mucin content increased significantly to 127% of the control after the administration of 30 mg/kg of Z-300, whereas that in the antral mucosa did not increase. The addition of Z-300 significant ly increased [H-3]-labeled mucin in the corpus region. In the antrum, biosynthetic activity showed no significant change by 10(-8)-10(-5) M of Z-300. These results suggest that Z-300 not only inhibits acid secr etion but may also promote gastric mucus metabolism in the corpus regi on.