Changes of gastric mucus glycoproteins with aspirin administration in rats

The qualitative changes of gastric mucus glycoproteins occurring after aspirin dosing in rats were further investigated. Mucus glycoprotein contents of test animals were 55 and 53% of the control value at 3 and 7 h after dosing, respectively. The glycoproteins were further fractionated by CM-Sepharose CL-6B chromatography. 5 fractions were separated, 1 unadsorbed (fraction 1) and 4 adsorbed (fractions 2-5). Ratios of the major fractions 1:2:4 were 36:47:17 for control, 40:35:25 3 h after aspirin dosing, and 47:33:20 7 h after aspirin administration. Fractions 1, 2, and 4 corresponded to sulfomucin and sialomucin (relatively high content of sialic acid), sialomucin, and neutral mucin, respectively. While the absolute amount of each mucus glycoprotein fraction decreased with aspirin administration, the diminution of fraction 2 was distinct.