Prostaglandin effect on the physical properties of gastric mucus glycoprotein and its susceptibility to pepsin.
The effect of 16,16-dimethyl prostaglandin E2 (DMPGE2) on gastric mucus glycoprotein viscosity, permeability to hydrogen ion and degradation by pepsin was investigated. Preincubation with DMPGE2 produced a marked enhancement in the glycoprotein viscosity. The increase was concentration dependent and at 2.6 X 10(-5)M DMPGE2 reached a value of 178%. Permeability measurements revealed that 2.6 X 10(-7)M DMPGE2 increased the retardation ability of the glycoprotein to hydrogen ion by 10%, while 22% increase was obtained with 2.6 X 10(-4)M DMPGE2. The results of peptic activity assay showed that DMPGE2 had no inhibitory effect on the rate of glycoprotein proteolysis, and actually a small stimulatory influence was consistently observed. The results suggest that prostaglandins beneficially affect the physical properties of mucus glycoprotein which are considered to be essential for the protective function of gastric mucus.