Effects of Peptides of the “Gut-Brain-Skin Triangle” on Drinking Behaviour of Rats and Birds

Abstract

Amphibian skin is an extraordinarily rich source of active peptides. Erspamer and co-workers undertook a systematic biological and chromatographic screening of the skin extracts of more than 500 different species of amphibians and discovered and characterized more than 40 active peptides (1, 2). Most of these peptides contain aminoacid sequence in their “active regions” analogous to mammalian peptides which act as neurotransmitters, autacoids, releasing factors or gastrointestinal hormones. Several of them, or at least substances chemically and biologically resembling them, have been identified in mammalian tissues, including the brain. Thus, the interest of experts in these peptides (particularly in those which have been found in mammalian brain and which exert on it intense and specific effects at extremely low concentrations) is now progressively shifting from their pharmacological to their physiological aspects.