Activities of antioxidant enzymes and Hsp levels in response to elevated temperature in land snail species with varied latitudinal distribution

Abstract

Land snails occupy a variety of habitats, with differing temperature and humidity regimes and exhibit a wide span of adaptations, to withstand abiotic condition changes. The present work's aim was to examine the correlation of habitat's thermal adversity in different Mediterranean type habitats with the land snail's antioxidant and heat shock responses. For this purpose, snails of different species from populations along a north–south axis from the islands and mainland of Greece were exposed to elevated temperature and antioxidant enzyme activities, and Hsp70 and Hsp90 levels were determined in their tissues. The ATP, ADP, and AMP levels and the adenylate energy charge (AEC) were also determined. The comparison of protein levels and enzymatic activities across time intervals revealed significant differences for all factors examined. While the gradation pattern over time for a given factor was similar in all populations the absolute values over time differed. Catalase activity and the Hsp90 protein levels had the higher contribution in separating the different species and populations, followed by the activity of glutathione reductase and Hsp70 protein levels which contributed to a lesser degree. In general, populations from the southern part of their distribution in Greece tend to display a faster increase than northern populations in induction levels of all factors examined. Our data seem to be in line with the concept of preparation for oxidative stress (POS) while the changes in the AEC indicate an early preparation to cover the energy demand for the induction and synthesis of antioxidant enzymes and Hsps.