Hemodynamic studies in acute venous stasis edema in rats.

An increase in venous pressure in the rat tail is known to result in acute edema. Acute venous stasis edema of the rat tail was induced by applying a force-controlled banding of standard tension (200 g) proximally for a period of 6-12 h. The hemodynamic changes of acute venous stasis edema were evaluated using non-invasive plethysmography, fluorescence angiography, computer thermography and invasive radioactive microsphere techniques. It is shown here that reduction of tail circulation to 40% of the control value is followed by prolonged vascular disorder characterized by genesis of reversible edema, increased total blood flow to the tail and decreased local cutaneous blood flow, without affecting the general hemodynamics. The cutaneous circulation (decreased blood flow) seems to be principally involved in the edemogenic response, whereas the deeper vessels (hyperemia) may or may not play a determinant role in acute experimental venous stasis edema in rats.