The use of the hamster stomach in vitro as an assay preparation for prostaglandins.

1. Hamster stomach strips in vitro are useful test preparations for the assay of prostaglandins E and F in the nanogram concentration range. Three-minute cycles can be used for long periods without spontaneous contractions or significant base-line instability.2. The mean percentage error and the precision index of six 4-point assays of prostaglandin E(2) were 7.8 and 0.057, respectively.3. The relative sensitivity to different prostaglandins was E(2)/E(1) approximately 1, E(2)/F(1alpha) approximately 65 and E(2)/A(1) approximately 400.4. These preparations were relatively insensitive to 5-hydroxytryptamine (prostaglandin E(2)/5-HT approximately 20,000) and histamine (prostaglandin E(2)/histamine approximately 200).5. These results suggest that the hamster stomach preparation can be used to differentiate between 5-hydroxytryptamine and prostaglandins.