The effects of low-intensity KAATSU resistance exercise on intracellular neutrophil PTX3 and MPO

Myeloperoxidase (MPO) has been suggested to have a role in atherosclerosis through its strong oxidative capacity. MPO-mediated formation of reactive oxidants is enhanced after exhaustive exercise. Low-intensity resistance exercise (LIRE) under the conditions of restricting muscle blood flow (KAATSU) has been reported to strengthen muscles, in a way similar to high-intensity resistance exercise. We investigated the effects of LIRE-KAATSU on neutrophil intracellular MPO and pentraxin 3 (PTX3), an inflammatory marker. Five control subjects and six patients with ischemic heart diseases (IHD) (pPCI 5, pCABG 1) have participated in this study. Each subject performed LIRE (20% 1RM leg extension, 4 sets, 30-15-15-15) under the conditions with or without KAATSU. Neutrophils were immunostained with a specific antibody to PTX3 and MPO and the density of these markers was measured by flow cytometry analysis (FACS). FACS and immunostaining studies showed the existence of PTX3 and MPO in neutrophils. LIRE did not particularly release PTX3 and MPO from neutrophils in healthy subjects under the conditions with or without KAATSU. The similar results were obtained in patients with IHD. These results suggest that the addition of KAATSU to LIRE did not enhance PTX3 and MPO release from neutrophils even in patients with IHD, which may be related to the safety of KAATSU, compared to high-intensity resistance exercises