CAPILLARY SUPPLY AND METABOLISM OF MUSCLE FIBERS.

Introduction THE ANATOMICAL arrangement of capillaries in muscle has been studied in detail for the first time by Ranvier, 64-66 and later by Spalteholz. 85 Subsequently, several workers investigated the number of capillaries in muscle at rest and in a variety of physiological states. * Histochemical studies of alkaline phosphatase disclosed high activity of this enzyme in muscle capillaries. † However, none of these investigations added new information to the arrangement of capillaries in muscle described by Ranvier and Spalteholz. All workers assumed that within a muscle each fiber is surrounded by an equal number of capillaries. In a previous communication 75 I have described in detail the results of histochemical studies regarding the relative activity of a number of enzymes in individual skeletal muscle fibers. The histochemical results were confirmed and complemented by quantitative biochemical assays. 16 During these histochemical investigations, considerable differences were noted between the number of