A sensitive biological assay for prostaglandin E and acetylcholine.

Superfused hamster stomach strip has been used in the bioassay of prostaglandin E2 (PGE2) and acetylcholine. The preparation proved very stable and had no spontaneous movements. The sensitivity to PGE2 (and PGE1) was in the range of 10(-9) g ml(-1) and to acetylcholine 10(-12) g ml(-1). After treatment with physostigmine the sensitivity to acetylcholine was 10(-15) g ml(-1). In acetylcholine determination the preparation is more sensitive than any other method.