Inducible protective processes in animal systems XV: Hyperthermia enhances the Ethyl methanesulfonate induced adaptive response in meiotic cells of grasshopper Poecilocerus pictus

Purpose: To understand the role of hyperthermia in adaptive response, Ethyl methanesulfonate (EMS) an anticarcinogenic agent, adapted meiotic cells of Poecilocerus pictus was used. Materials and methods: Based on the pilot toxicity study, the effective higher temperatures of 40 °C and 45 °C for 15 or 30 min were chosen. P. pictus were treated with conditioning (L) or challenging (H) doses of EMS and 2 h time lag (TL) between these doses (L-2 h-H) was employed. Different treatment schedules were used to analyze the influence of hyperthermia on EMS induced adaptive response namely (i) pre treatment; (ii) inter treatment; (iii) post treatment and (iv) cross adaptation. After each treatment schedule, animals were sacrificed at 12, 24, 36 and 48 h recovery times, testes were processed for meiotic chromosome preparations and anomalies were analyzed. Results: The frequencies of anomalies induced by both conditioning and challenging doses of EMS were significantly higher (p < 0.05) compared to those of the control and hyperthermia groups. The combined treatments resulted in 44–50% reduction compared to additive effect of EMS. The pre, inter, post and cross adaptation treatments with hyperthermia significantly reduced the frequencies of chromosomal anomalies compared to the challenge and combined treatments with EMS at all recovery times (p < 0.05) tested. Conclusion: There is a protection against EMS induced anomalies by hyperthermia in in vivo P. pictus. As far as our knowledge is concerned, this is the first report to demonstrate that hyperthermia enhances the EMS induced adaptive response in in vivo meiotic cells