Gene expression profiling in the heart following exposure of rats to heat acclimation, its loss and re-induction.. Rattus norvegicus

To understand faster reinduction of heat acclimation, in this investigation we studied global stress associated genomic response during acclimation, following its loss and re-induction. Nylon cDNA Atlas Array was used. Collectively, the study comprised nine experimental groups of which six characterized experimental basal conditions: Controls-untreated, Short and Long term heat acclimated groups ( exposure to environmental heat at 34oC for 2 or 30 days respectively), Deacclimated group (24oC for 1mo) and Reacclimated groups (2d at 34oC following the deacclimation protocol). Three additional experimental groups: Controls, Short and Long term and Reacclimated rats (as above) were tested for genomic responses following subjection to heat stress at 41oC. Because of a dichotomy between genomic and physiological responses we hypothesize thst rapid reacclimation is linked to reprograming of gene expression. Keywords: heart, Left ventricle Overall design: Overall design: 27 samples, 9 treatments, 3 pooled samples for each: 1) Control untreated rats 2) Control, heat stressed rats 3) Short term heat acclimated rats 4) Short term, heat stressed-heat acclimated rats 5) Long-term heat acclimated rats 6) Long-term, heat stressed-heat acclimated rats 7) One mo deacclimated rats 8) Rats exposed to long-term heat acclimation, deacclimation and reacclimation for two days 9) Rats exposed to heat stress following long-term heat acclimation, deacclimation and reacclimation for two days Series data table appended below represents the normalized log2 ratio of geomeans defined as treatment divided by control.