Stress reactions and endorphinergic systems.

The discovery of the endorphins, a family of distinctive endogenous peptides possessing opiate-like activity, which appear to play a central role in the regulation of pain and other vegetative functions, prompted several investigations in animals and in man as to their possible role in stress phenomena. Several different strategies have been employed: Measurement of concentrations and release of endorphins in different brain areas, measurement of pain sensitivity and of different behavioral variables of animals before and after stress stimuli (with and without the application of the specific opiate antagonist naloxone), measurement of actual levels of endorphins in CSF and plasma of patients with different types of neuroses and psychoses. The present state of research in this field is summarized.