Effects of caffeine and theophylline on prostaglandin production by guinea-pig endometrium.

Caffeine and theophylline increased prostaglandin output from day 7 and day 15 guinea-pig endometrium in culture. Ryanodine and forskolin had no effect on endometrial prostaglandin output. These results show that methylxanthines stimulate endometrial prostaglandin synthesis. However, the intracellular mechanisms involved apparently do not entail an increase in the intracellular free concentration by activation of a ryanodine-sensitive receptor or an increase in the cyclic AMP concentration.