REDUCTION OF REPERFUSION INJURY IN RAT SKELETAL-MUSCLE FOLLOWING ADMINISTRATION OF CINNAMOPHILIN, A NOVEL DUAL INHIBITOR OF THROMBOXANE SYNTHASE AND THROMBOXANE A(2) RECEPTOR

We used cinnamophilin, a novel dual inhibitor of thromboxane synthase and thromboxane A(2) (TXA(2)) receptor, and superoxide dismutase (SOD) with catalase to examine their protective effect against reperfusion injury in rat skeletal muscle. In 5 groups of 6 Wistar rats three hour s of ischaemia were induced in one hind limb by application of a tourn iquet to the proximal thigh; the contralateral limb served as an inter nal, nonischaemic control. The first group did not receive any drug no r was it reperfused. In the other four groups, normal saline (reperfus ion control), dimethylsulphoxide (DMSO), cinnamophilin, or SOD with ca talase was given before removal of the tourniquet and one hour of repe rfusion followed. Skeletal muscle injury was measured by a quantitativ e spectrophotometric assay of triphenyltetrazolium chloride (TTC) redu ction and by muscle weight gain. One hour of reperfusion significantly (p < 0.05) lowered TTC reduction in ischaemic limbs in the reperfusio n control group in comparison with the rats with 3h ischaemia alone. A mong the four reperfusion groups, only the cinnamophilin group had sig nificantly lower decrease of TTC reduction and significantly lower mus cle weight gain. These results demonstrate the protective effect of ci nnamophilin against reperfusion injury of the ischaemic skeletal muscl e in rats.