Gastric mucosal formation of prostanoids and the effects of drugs

Prostanoids can be formed throughout the gastrointestinal tract, and qualitative gas chromatography--mass spectrometry has shown that human gastric mucosa can produce PGD2, PGE2, PGF2 alpha 6 keto-PGF1 alpha, thromboxane A2 and lipoxygenase material. Quantitative gas chromatography--mass spectrometry has shown that human gastric mucosa homogenized in Krebs' solution yields mainly 6-keto-PGF1 alpha, with smaller amounts of PGD2 PGE2 and PGF2 alpha. However, the sources of these products and their roles in the gastric mucosa have not been fully elucidated. Recent research from other laboratories indicates that thromboxane formation may be important in gastric ulceration. Our studies with rats in vivo have detected no significant effect of carbenoxolone or deglycyrrhized liquorice on the content of radio-immunoassayable PGE, 6-keto-PGF1 alpha and TXB2 extracted from rat gastric corpus mucosa. The anti-ulcer effect of these drugs in rats therefore does not seem to involve prostanoids.