Comparison of the solution of histidinetryptophan- alfacetoglutarate with histidinetryptophan- glutamate as cardioplegic agents in isolated rat hearts: an immunohistochemical study

Abstract

IntroductionCardiac arrest during heart surgery is a common procedure and allows the surgeon to perform surgical procedures in an environment free of blood and movement. Using a model of isolated rat heart, the authors compare a new cardioplegic solution containing histidine-tryptophan-glutamate (group 2) with the histidine-tryptophan-alphacetoglutarate (group 1) routinely used by some cardiac surgeons.ObjectiveTo assess caspase, IL-8 and KI-67 in isolated rat hearts using immunohistochemistry.Methods20 Wistar male rats were anesthetized and heparinized. The chest was opened, cardioctomy was performed and 40 ml/kg of the appropriate cardioplegic solution was infused. The hearts were kept for 2 hours at 4ºC in the same solution, and thereafter, placed in the Langendorff apparatus for 30 minutes with Ringer-Locke solution. Immunohistochemistry analysis of caspase, IL-8, and KI-67 were performed.ResultsThe concentration of caspase was lower in group 2 and Ki-67 was higher in group 2, both P<0.05. There was no statistical difference between the values of IL-8 between the groups.ConclusionHistidine-tryptophan-glutamate solution was better than histidine-tryptophan-alphacetoglutarate solution because it reduced caspase (apoptosis), increased KI-67 (cell proliferation), and showed no difference in IL-8 levels compared to group 1. This suggests that the histidine-tryptophan-glutamate solution was more efficient than the histidine-tryptophan-alphacetoglutarate for the preservation of hearts of rat cardiomyocytes.

Heart defibrillation: relationship between pacing threshold and defibrillation probability

“…The present study shows that, within certain limits, the longer the pulse duration is, the lower is the threshold intensity for pacing and defibrillation, as expected for the stimulation of excitable tissues [19, 20]. Herein, we show for the first time, to the best of our knowledge, the stimulation and defibrillation SxD curves for the same hearts, considering an applied E homogeneously, which generated values more reliable and preparation independent.…”

The microvascular endothelial glycocalyx: An additional piece of the puzzle in veterinary medicine

“…The most established and successful technique for direct visualisation of the eGlx involves vessel perfusion and staining ( Hegermann et al, 2016 ). Initial vessel cannulation is required prior to flushing with solutions of physiological oncotic and electrolyte properties ( Kimura et al, 2001 , Oliveira et al, 2014 ) to remove plasma proteins and prevent eGlx dehydration ( Jacob et al, 2007 , Ebong et al, 2011 ). Following this, vessels are prepared for electron microscopy by perfusion with fixative solutions such as glutaraldehyde in cacodylate buffer prior to perfusion with special stains that bind heavy metal cations to proteoglycans within the eGlx ( Curran et al, 1965 , van den Berg et al, 2003 ).…”