CASCADE COUPLING REGULATION BY LOCAL AND CENTRAL CONTROL MECHANISMS ON THE MICROCIRCULATION IN RABBIT SKELETAL MUSCLE.

Effects of local and central control mechanisms by tissue PO//2 and the autonomic nervous system on the microcirculation were investigated in the rabbit tenuissimus muscle under vital microscopic observation. After the preparation, the tenuissimus muscle was placed on a pair of prisms so as to locate the main supplying artery and vein at the center in the space between them. The prisms were connected to the light source with bundles of optical fiber. The microcirculation was observed on a TV monitor through a microscopic-TV camera. Microcirculatory responses to the electric stimulation of the carotid sinus nerve were measured at the state of different PO//2 in Tyrode solution suffusing the muscle. When PO//2 in Thyrode solution was elevated, capillary red cell velocity and the perfused capillary density were decreased both at control and during stimulation but to different extents. Regression lines between these changing rates and PO//2 levels revealed that the reflex efffect on velocity and density at 20mmHg was some 1. 3 and 4. 8 times enhanced at 80mmHg respectively.