Effect of an anti-ulcer agent, 2'-carboxymethoxy-4, 4'-bis (3-methyl-2-butenyloxy) chalcone (SU-88), on the biosynthesis of gastric sulfated mucosubstances in restrained and water-immersed rats.

2'-Carboxymethoxy-4,4'-bis(3-methyl-2-butenyloxy) chalcone (SU-88) has an anti-ulcer effect which is considered to increase the resistant factors of the gastric mucosa. In order to clarify the mechanism of the action of SU-88, the biosynthesis of gastric sulfated mucosubstances (SMS) in vivo and in vitro was investigated in rats with gastric erosion induced by restraint and water-immersion. The incorporation of 35S-sulfate into gastric SMS was significantly reduced 18 hr after the onset of stress. Pretreatment with SU-88 (500 mg/kg, p.o., X 10 days) prevented a reduction in the incorporation of 35S-sulfate due to stress when 35S-sulfate was administered in vivo. On the contrary, the incorporating activity of 35S-sulfate into the SMS in the isolated rat gastric mucosa with erosion was significantly increased 12 hr after the onset of stress, as compared with that of the control group in vitro. The incorporation of 35S-sulfate into the SMS was still further increased by the oral administration of SU-88. The mode of action of SU-88 on the biosynthesis of SMS was discussed.