Thermal Stress Induced Alterations in Tissue Protein, Lipid Peroxidation and Activities of Lactate Dehydrogenase, Acetylcholinesterase and Catalase in the Earthworm Eudrilus eugeniae (Kinberg)

Aim: To evaluate the effects of different temperatures exposures on tissue protein and certain stress indicating enzymes of the earthworm Eudrilus eugeniae.

Methodology: The tissue protein content, lipid peroxidation (LPX) level and activities of lactate dehydrogenase (LDH), acetylcholinesterase (AChE), catalase were studied in the earthworms exposed to 4°C, 30°C, 35°C and 40°C for 15 and 30 minutes durations using a standard protocol.

Results: The highest tissue protein (216.64 mg/g tissue) was recorded at 35°C with 30 min exposure and the lowest (123.19 mg/g tissue) at 4°C with 15 min exposure. LDH activity was the highest (0.14 U/mg protein) at 35°C with 15min exposure and the lowest (0.006 U/mg protein) at 30°C. The maximum AChE activity (0.029 U/mg protein) was observed at 30°C with 15min exposure and the minimum (0.005 U/mg protein) at 35°C with 30 min exposure respectively. LPX level was the highest (0.15 nmol/mg protein) at 4°C with 30min exposure and lowest (0.07 nmol/mg protein) at 35°C with 30 min exposure. Catalase activity was the maximum (0.11 U/mg protein) at 30°C with 15 min exposure and minimum (0.02 U/mg protein) at 35°C with 15 min exposure.

Conclusion: The study indicated that tissue protein; LPX level and enzyme activities could be useful biomarkers to study the organismal impact of thermal stress due to climate change.