Does an Acute Bout of Exercise Performed at the Maximal Fat Oxidation Rate Have an Impact on Human Adipose Tissue Microvascular Endothelial Cells?

Abstract

The adipose tissue (AT) vasculature ensures healthy tissue function, supporting whole-body homeostasis. Endothelial cells (EC) line vascular capillaries and control their growth (i.e. angiogenesis). Exercising at an intensity eliciting maximal fat oxidation rate (maxFOR) increases AT blood flow and might support vascular remodelling. Yet, the impact of maxFOR on AT EC remains unknown. The workload required to achieve maxFOR was determined for 11 healthy females. Blood samples were collected pre-, immediately post- and 3h post- a 45-minute bout of aerobic exercise performed at maxFOR. Serum was isolated to treat Human Adipose Microvascular EC (HAMEC) to assess cellular behaviour and gene expression. Serum free fatty acid (FFA) concentration increased post-exercise for all participants. HAMEC had reduced migratory capacity and increased Fatty Acid Binding Protein 4 (FABP4) gene expression when treated with serum collected 3h post-exercise. Exercise at maxFOR may stabilize EC and prime AT capillaries for efficient FFA transport and uptake.