Healthy And Diseased Heart Chapter 11 Summary

Chapter 11 paper summary In this paper Regulation of Sarcolemmal Transport of Substrates in the Healthy and Diseased Heart written by Jan F. C. Glatz et al. they are discussing the role of long chain fatty acids or LCFA and glucose balances when it comes to healthy and diseased hearts. LCFAs and glucose are predominate for cardiac metabolic energy production meaning that these two substrates are the main energy providers when it comes to a healthy functioning heart. When a heart is healthy these two substrates are well balanced and are utilized to the fullest, but when this balance is thrown off it results in different cardiac diseases. These chronic cardiac diseases usually have one or the other substrate being utilized more. If glucose is utilized more it can lead to cardiac hypertrophy or failure, but when LCFAs are used more it leads to diabetic cardio …show more content…
Cardiac muscle contractions and insulin induced CD36-mediated LCFA uptake and GLUT4-mediated glucose uptake both use different signaling pathways. With insulin it activates phosphatidyl-inositol-3 (PI-3) and cellular contractions activates 5 prime adenosine monophosphate kinase (AMPK). Substrate uptake induced by insulin is additive to contraction-induced substrate uptake. They found that both CD36 and GLUT4 reside in similar intracellular storage compartments as found when they identified GLUT4 that was both in large and small depos. This then represents GLUT4 specific pre-endosomal storage compartments and recycling endosomal compartments. The small depos were then subdivided into transferrin receptor-positive depots recruited by contractions and transferrin receptor-negative depots recruited by insulin. They saw that co-localization of CD36 and GLUT4 was not observed and thus concluded that GLUT4 specific pre-endosomal storage as an intracellular depot of CD36 could be