VASCULAR COMPLIANCE AND VASOCONSTRICTIVE REACTIONS IN RAT HINDLIMBS -COMPARISON BETWEEN STORAGE TEMPERATURES OF -1-DEGREES-C AND 4-DEGREES-C

The Vascular compliance and contractility of vascular smooth muscle of rat freshly amputated hindlimbs and hindlimbs preserved at -1 degrees C for 12, 24, 48, and 72 hr were evaluated using a fresh blood extrac orporeal circulatory system. Vascular compliance was measured under ph ysiologic circulatory conditions (blood pressure of the amputated limb was maintained at 80 to 150 mmHg). Vascular compliance after storage at -1 degrees C for 12 hr or longer decreased significantly from that of freshly amputated limbs (p<0.01). To evaluate the contractility of vascular smooth muscle, the arterial blood pressure in the amputated l imbs was transiently increased with injections of norepinephrine. The contractility after storage at -1 degrees C for up to 24 hr was not di fferent from that of freshly amputated limbs. However, it decreased si gnificantly after 48 hr or longer. A comparison of these results with an earlier study that used identical methods to investigate limbs pres erved at 4 degrees C suggested that storage at -1 degrees C was inferi or to that at 4 degrees C with respect to vascular compliance, but was superior to storage at 4 degrees C with respect to smooth muscle cont ractility.