Neuroleptic-like activity of peptides related to [DES-TYR1] γ-endorphin: Structure activity studies

Abstract

The potency of various fragments of γ-endorphin (β-LPH61–77) was compared on their ability to facilitate extinction of pole-jumping avoidance behavior and their effects in two “grip tests” used as measures of neuroleptic-like activity. It appeared that β-LPH66–77 is the shortest sequence which shows potencies in the three tests comparable to that of DTγE (β-LPH62–77). The activity of β-LPH67–77 was less. It is proposed that β-LPH66–77 rather than DTγE represents an endogenous neuroleptic-like neuropeptide which may play a key role in psychopathology.