Coronary Sinus Integrated Lactate Decreases After Ischemia and Reperfusion with GGA Induced hsp70

Abstract

<h3>Purpose: Background</h3> Ischemia reperfusion(IR) increases lactate. No one has examined if cardiac-specific coronary sinus lactate(CSL) can be reduced with prior cytoprotective heat shock protein 70(hsp70i) induction. We previous demonstrated improved IR in vivo with inducted hsp70i. Geranylgeranylacetone(GGA), an hsp70i inducer, has never been administered IV preischemically. Interventions to decrease CSL may improve clinical parameters. <h3>Methods</h3> Rabbit hearts underwent 30 cold cardioplegic ischemia then 60 min reperfusion. One group received IVGGA 24 hours prior(GGA+) and the other vehicle(GGA-). CSlactate was collected prior to ischemia and throughout reperfusion. We aimed to determine IVGGA effects on myocardial hsp70i and lactate. Hsp70 western blot was performed. <h3>Results</h3> Baseline CSlactate was similar between GGA+ and GGA-(Figure 1). Both peaked CSlactate at 1 minute reperfusion. However GGA+ peak was less. At every time point GGA+ was less. GGA+ CSlactate continued to decrease throughout reperfusion however in GGA- CSlactate increased later. Integrated CS lactate area was less for GGA+(Figure 1). <h3>Conclusion</h3> In summary, protective IVGGA resulted in five lactate benefits: lactate was less at 1 minute reperfusion peak,decreased faster in early reperfusion, was reduced at all time points, does not have a second rise and lastly results in overall less integrated lactate production in GGA+. GGA induced hsp70. IVGGA may have clinical applications in endothelial protection in IR and COVID.