Abstract

A fair 02 supply to mitochondria of the skeletal muscles depends by both the partial 02 pressure in capillaries and the myoglobin concentration into muscular fibre. The myoglobin concentration is constant in the cardiac muscle of all the adults mammals; on the contrary in the skeletal muscles it undergoes to variation depending from the adaptation to low 02 pressure or to increased metabolic request induced by the physical training. The myoglobin acts as being partially deoxygenated. This implies an oxygen gradient bound to the protein and progressing from the periphery to the axis of the fibre. The same gradient, which have a slope depending on the shape of the dissociation curve of myoglobin, is very needfull for the contribution of myoglobin to maintain a02 flux from capillaries to mitochondria. Verf.-Referat