Chemical identification of the excitatory substance released in Helix heart during stimulation of the extracardial nerve

Abstract 1. 1. A Loewi set-up of two snail showed that excitation of the nerve going to one heart caused excitation of the second heart. 2. 2. 5-HT was detected (spectrophotometrically and chromatographically) in the “excited” perfusate. 3. 3. There was a second factor in the perfusate which could be a derivative of arginine. 4. 4. The transmitter role of 5-HT in the snail is discussed.