Discussion
Concluding a protective effect of hypothermia on the experimental electrode insertion trauma can be described by an anti-apoptotic and anti-inflammatory reaction.
Material and methods
The cochleae of C57Bl6/J mice (Charles River®, Freiburg, Germany) are cultured for 24 hours at 37°C and 32°C after inserting a fishing line through the round window simulating an insertion trauma. The resulting effect was evaluated for the apoptotic reaction - B-cell-Lymphoma-2-Associated-X-Protein (BAX), B-Cell-Lymphoma-2-Protein (BCL2) and Cleaved-Caspase-3 (CC3) -, the inflammatory response - Tumor-Necrosis-Factor-Alpha (TNFα), Interleukin-1-Beta (IL-1Imm) and Cyclooxygenase-2 (COX2) - and proliferation process - Transforming-Growth-Factor-Beta-1 (TGFβ1) - using immunohistochemistry and real-time PCR technique. A minimum of 12 cochlea per experiment were used.
Methods
The cochleae of C57Bl6/J mice (Charles River®, Freiburg, Germany) are cultured for 24 hours at 37°C and 32°C after inserting a fishing line through the round window simulating an insertion trauma. The resulting effect was evaluated for the apoptotic reaction - B-cell-Lymphoma-2-Associated-X-Protein (BAX), B-Cell-Lymphoma-2-Protein (BCL2) and Cleaved-Caspase-3 (CC3) -, the inflammatory response - Tumor-Necrosis-Factor-Alpha (TNFα), Interleukin-1-Beta (IL-1Imm) and Cyclooxygenase-2 (COX2) - and proliferation process - Transforming-Growth-Factor-Beta-1 (TGFβ1) - using immunohistochemistry and real-time PCR technique. A minimum of 12 cochlea per experiment were used.
Results
A pro-apoptotic situation was observed in the normothermic group (BAX, CC3 ˃ Bcl2) whereas an anti-apoptotic constellation was found at 32°C culture conditions (BAX, CC3 < Bcl2). Furthermore the effect of the IT knowing to effect the pro-inflammatory cytokine (TNFα, Il1β) and enzyme (COX2) expression has been reproduced. This reaction was reversed with the application of therapeutic hypothermia resulting in significant lower pro-inflammatory cytokine (TNFα, Il1β) and enzyme (COX2) expression. TGFβ1 was increased by hypothermia.