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 two neuropeptides, Met-enkephalin (Peptid-M, LUPEX®) and α-melanocyte stimulating hormone (α-MSH). Both peptides exhibited significant and synergistic cytoprotective effects. The best therapeutic efficacy was obtained with Met-enkephalin and α-MSH mixture 3-5 : 1. Significant cytoprotective action on ethanol induced lesions was also observed by means of two thymus peptide immunomodulators, Thymus Peptide C® and JAN 50®. Thymus Peptide C® exhibited a more significant synergistic effect with Met-enkephalin than JAN 50®. In addition to the cytoprotection of rat gastric mucosa, Met-enkephalin also induced statistically significant and dose dependent Straub tail response versus control in miče. Haloperidol, naloxone and Peptide-D antagonised its effects. NMR spectrospic data supported molecular interaction of Met-enkephalin and haloperidol, while neutralization of Met-enkephalin induced Straub tail response by means of Peptide-D indicated the presence of new non-opioid (naloxone independent) receptor system containing Peptide-D sequence (calpastatin 201-205 aa).