The importance of PAPS in determining sulfation in gastrointestinal mucosa.

The in vitro sulfation of glycoproteins, mucopolysaccharides and lipids was studied with rat stomach, duodenum and colon mucosal scrapings. In the presence of Na2 35SO4, the incorporation of label was colon greater than stomach greater than or equal to duodenum. In the presence of [35S] 3'-phosphoadenosine 5'-phosphosulfate (PAP35S), the incorporation of label was colon = stomach greater than duodenum. The 35S was incorporated into glycoprotein, mucopolysaccharide and sulfatide. It is suggested that the availability of PAPS may be an important factor in determining the differences in sulfation previously observed histochemically in several species, namely that in vivo colonic mucosa far exceeds stomach mucosa in synthesis of sulfated polyanions.