Marianne Ruud, Michael Frisk, Arne Olav Melleby, Per Andreas Norseng, Belal A Mohamed, Jia Li, Jan Magnus Aronsen, Ingunn E Setterberg, Joanna Jakubiczka, Isabelle van Hout, Sean Coffey, Xin Shen, Ståle Nygård, Ida G Lunde, Theis Tønnessen, Peter P Jones, Ivar Sjaastad, Lars Gullestad, Karl Toischer, Cristen P Dahl, Geir Christensen, William E Louch
Mechanical load is a potent regulator of cardiac structure and function. Although high workload during heart failure is associated with disruption of cardiomyocyte t-tubules and Ca2+ homeostasis, it remains unclear whether changes in preload and afterload may promote adaptive t-tubule remodelling. We examined this issue by first investigating isolated effects of stepwise increases in load in cultured rat papillary muscles. Both preload and afterload increases produced a biphasic response, with the highest t-tubule densities observed at moderate loads, whereas excessively low and high loads resulted in low t-tubule levels...
April 30, 2024: Journal of Physiology