Consequences of Atrial or Ventricular Tachypacing on the XXXX Proteins (HSP) level of Expression and Phosphorylation.

@entity1 @entity712 @entity563 @entity13678 @entity235 @entity1457 @entity955 @entity25485
BACKGROUND: Uncontrolled @entity955 ( @entity955 ) results in complex changes in the cardiomyocyte electrical and contractile functioning that promote @entity13678 and the continuation of @entity955 . Recently there has been a growing interest in understanding the role of @entity1457 proteins (HSPs), which are cytoprotective molecular chaperones, in the pathophysiology of @entity955 . Several groups have examined HSP expression in @entity1 with @entity955 but have yielded mixed results. To allow for better consistency and reproducibility between subjects, we utilized @entity235 models to reproduce AFpromoting conditions to better investigate the role of HSPs in the pathophysiology of @entity955 . METHODS: @entity955 promoting conditions were simulated in @entity235 models with fifteen adult mongrel @entity235 (20.6 to 36.0 kg) divided into three groups: (1) Control (n=5), (2) two week ventricular tachypacing (VTP) induced @entity712 ( @entity712 ) (n=5), and (3) one week @entity955 ( @entity955 ) (n=5). Quick frozen right atrial free wall tissue samples were used for protein isolation and were analyzed via Western blotting with data was expressed as a relative ratio and were analyzed using a two-tailed, unpaired ttest and significance was set at p < 0.05. The expression levels of HSP 90, 70, and 25 were studied along with the phosphorylation status of @entity25485 at @entity563 -78. RESULTS: We first examined the effects of the @entity955 and @entity712 heart models on the expression of a select group of HSPs via Western Blot. We found that there was no significant difference in levels of expression of HSP 90, 70, or 25 when either @entity955 or @entity712 models were compared to control @entity235 . The phosphorylation status of @entity25485 was significantly decreased in the @entity712 @entity235 model when compared to control (p < 0.0111) and it tended towards a decrease in the @entity955 @entity235 model when compared to control (p=0.0923). CONCLUSION: This study showed that even though the expression levels of HSPs may remain constant, there are protein phosphorylation and dephosphorylation events that occur in @entity955 that may have important consequences in its pathophysiology. It is therefore necessary to investigate the full scale of HSP modifications during @entity955 and @entity955 -promoting conditions.
