A simple and efficient method for studying neurotransmitter release in vitro by a radiotracer technique.

A method which allows measurement of neurotransmitter release from isolated preparations has been developed. With this method release of 3H-acetylcholine from guinea pig ileum and rabbit jejunum could be studied after preincubation of the preparations with 3H-choline. The release of noradrenaline from guinea pig vas deferens could also be measured after preincubation with 3H-noradrenaline. The method is based on a device which allows experiments on 4 preparations at the same time, including incubation, field stimulation and collection of fractions for counting of radioactivity. With the purpose of obtaining a simple and inexpensive device for stimulating the tissue preparations electrically, a physiological stimulator distributor (PSD) was constructed. It is concluded that the described method constitutes an inexpensive simple and quick means of studying neurotransmitter release from isolated tissues.