Preincubation of L929 Line Fibroblasts with Synthetic Leu-Enkephalin TYR-D-ALA-GLY-PHE-LEU-ARG Preserves Their Proliferative Potential under Cold Stress

Under cold stress, the effect of synthetic leu-enkephalin (TYR-D-ALA-GLY-PHE-LEU-ARG) on the apoptosis, necrosis, and proliferative properties of fibroblasts of the L929 cell line was studied in a monolayer without damage and with a “wound surface.” It was proven that cold stress initiates the apoptosis and necrosis and slows down the cell proliferation in damaged and undamaged monolayer of L929 line fibroblasts. Preincubation of the cells with synthetic leu-enkephalin before modeling the cold stress leads to a probable ( p < 0.05) decrease in the number of fibroblasts with morphological traits of necrosis and apoptosis and a probable ( p < 0.05) increase in the proliferative potential of the cells in the intact monolayer and with a wound surface. It was found that the protective effect of synthetic leu-enkephalin is dose-dependent and differs significantly under cold stress and during wound healing. The largest efficiency of synthetic leu-enkephalin in preventing cell apoptosis and stimulating cell proliferation under cold stress is observed at concentrations of 10 and 100 μg/L.