Non-nutritional Blood Flow in Skeletal Muscle Determined with Hydrogen Gas

The total limb blood flow, total muscular blood flow and effective muscular blood flow were simultaneously determined by KetySchmidt method applying hydrogen gas and hydrogen wash-out technique at rest and during exercise in 35 dogs. Applicability of continuous recording and unnecessity of blood-sampling made the method using hydrogen gas superior to others. Total blood flow (7.87±3.77ml/min/100g) was significantly greater than effective blood flow (4.73±1.90ml/min/100g) in resting dog muscle, indicating that a part of the blood circulates through the tissue non-effectively. In other words, in resting muscle, there is non-effective (non-nutritional) blood flow which passes through “functional shunt”. One of the roles played by this non-effective flow seems to be “reserve” for the increase of local needs, especially for hyperemia by mild exercise. This conclusion was reached by the fact that the increase in total muscular blood flow during mild exercise was less remarkable, while effective muscular blood flow was remarkably increased. The significant difference obtained between the total limb blood flow (10.99±4.59ml/min/100g) and the total muscular blood flow indicates possible existence of A-V-A in skin.