Protective effects of Met-enkephalin on alcohol induced gastric lesions

The model of ethanol induced gastric lesions is useful in the evaluation of gastric cytoprotection. We used it to measure cytoprotective effects of tw o neuropeptides, Met-enkephalin (Peptid-M, LUPEX(R)) and alpha -melanocyte stimulating hormone (alpha -MSH). Both peptides exhibited significant and s ynergistic cytoprotective effects. The best therapeutic efficacy was obtain ed with Met-enkephalin and alpha -MSH mixture 3-5:1. Significant cytoprotec tive action on ethanol induced lesions was also observed by means of two th ymus peptide immunomodulators, Thymus Peptide C(R) and JAN 50(R). Thymus Pe ptide C(R) exhibited a more significant synergistic effect with Met-enkepha lin than JAN 50(R). In addition to the cytoprotection of rat gastric mucosa , Met-enkephalin also induced statistically significant and dose dependent Straub tail response versus control in mice. Haloperidol, naloxone and Pept ide-D antagonised its effects. NMR spectrospic data supported molecular int eraction of Metenkephalin and haloperidol, while neutralization of Met-enke phalin induced Straub tail response by means of Peptide-D indicated the pre sence of new non-opioid (naloxone independent) receptor system containing P eptide-D sequence (calpastatin 201-205 aa).