Investigations of capillary network in the myocardium, skeletal muscles, and other organs by modified Gomori's method for determination of acid phosphatase activity.

A modification of Gomori's sulfide method for the determination of acid phosphatase activity is presented, which visualizes the walls of all capillaries in the myocardium, skeletal muscles, synovial membranes, and some other organs (liver, kidney). Blocks of investigated organs (edge lengths 2--3 mm) are cold-fixed in acetone for 2--3 days. Fixed frozen tissues are cut to sections 90--120 micrometer thick and incubated for 2--3 days in an incubation mixture (1% lead/II) acetate, 90 ml; acetate buffer solution pH 6.2, 10 ml; 2% sodium beta-glycerophosphate 1 ml. The sections are then processed with 0.5% sodium sulfide solution for 10--15 min and embedded into glycerine-gelatin gel. In preparations processed in this way, acid phosphatase is visualized on the walls of all capillaries and precapillaries, makig visible the capillary network. In addition to the capillaries, the transverse striation of myofibrils is visualized as well. The described method is useful for investigating not only the cytochemistry of the vascular wall, but also the blood supply to the myocardium, skeletal muscles, and other organs in both normal and pathological states.