Effects of L-proline on cellular responses of hen erythrocytes subjected to thermal stress

Little is known on the protective effects of L-proline on hen erythrocytes. The aim of the study was to determine the protective effects of this amino acid at concentrations of 50 ?g/mL, 100 ?g/mL, 200 ?g/mL in hen erythrocytes subjected to temperatures 41 ?C, 43 ?C and 45 ?C for 1 h and 4 h. The following cellular parameters were determined: viability, morphological alterations, caspase 3/7 activity, heat shock protein HSP70 1A activity and glutathione level. The results showed that exposure to 43 ?C and 45 ?C resulted in a decrease of viability and increased morphological alterations of the non-treated erythrocytes. Caspase 3/7 activity was increased only at 45 ?C, however HSP70 1A activity and glutathione level were increased in the temperature-dependent manner. On the other hand, erythrocytes additionally exposed to L-proline showed alterations of the parameters when compared to the non-treated cells. L-proline at 50 ?g/mL and 100 ?g/mL increased caspase 3/7 activity at both 41 ?C and 43 ?C, however it was less augmented at all the concentrations at 45 ?C. Glutathione level was decreased in heat-stressed (at 43 ?C and 45 ?C) hen erythrocytes treated with L-proline (at 50 ?g/mL and 100 ?g/ mL) but it was increased at 200 ?g/mL. HSP70 1A activity was augmented in a concentration- and temperaturedependent manner. The results indicate that proapoptotic or antiapoptotic effects of L-proline depend on its concentration and temperature of heat stress and thermoprotective effects induced by the amino acid on some parameters in hen erythrocytes may be a result of stimulation of antioxidative defense and stimulation of HSP70 1A activity.

Automated summary

The study found that L-proline has protective effects on heat-stressed hen erythrocytes, with the specific effects depending on the concentration and temperature of the amino acid. L-proline may exert thermoprotective effects on some parameters in hen erythrocytes by stimulating HSP70 1A activity and antioxidative defense.