Blood flow and transport of free fatty acids in striated muscle under chronic ischemia.

Three weeks of ischemia of the right hind limb in rat produced by ligature and severing of the right common iliac artery, resulted in changes in FFA transport and blood flow in the regenerating tibialis muscle. FFA transport was measured using i.v. administered palmitate-1-14C bound to albumin. Uptake of palmitate-1-14C or 86Rb 90 s after i.v. administration was decreased in ischemic tibialis muscle, whereas no apparent effect of ischemia on the contralateral muscle was seen. Plasma FFA outflow rate measured according Beker and Rostami was not affected by the presence of an ischemic extremity in comparison with control animals. The plasma FFA inflow rate into the ischemic muscle was markedly decreased to values of 6.5 mmumoles FFA/min/g whereas in control animals values were 18.8 mmumoles FFA/min/g wet tissue. Decreased FFA inflow rate to the ischemic tibialis muscle was due to the decreased radioactivity of palmitate-1-14C in the muscle under the conditions of a constant plasma FFA pool. Differences in the uptake of palmitate-1-14C in tibialis muscle were dependent upon the muscle blood flow, which was markedly decreased in the ischemic muscle on indirect measurement with 86Rb or with the 133Xe clearance.