TC-99M SESTAMIBI LEG SCINTIGRAPHY FOR NONINVASIVE ASSESSMENT OF PROPIONYL-L-CARNITINE INDUCED CHANGES IN SKELETAL-MUSCLE METABOLISM

Carnitine derivatives, such as propionyl-L-carnitine (PLC), have been shown to improve walking distance in patients with obstructive periphe ral artery disease (PAOD). The aim of this study was to ascertain whet her technetium-99m sestamibi leg scintigraphy may be a useful tool in the evaluation of changes in skeletal muscle metabolism induced by chr onic therapy with PLC. Twenty patients with clinical and instrumental evidence of PAOD were randomly assigned to a 3-month period of therapy with either PLC or placebo. Rest Tc-99m-sestamibi leg scintigraphy an d echo-Doppler sonography were performed on all subjects immediately b efore and upon completion of the treatment period. At the end of the p rotocol the following results were observed in patients who underwent PLC administration: (a) a significant increase in both thigh and calf Tc-99m-sestamibi uptake, in comparison with baseline values (P<0.001); (b) the absence of statistically significant modifications of Doppler blood flow indices of the lower limbs. In conclusion, after chronic a dministration of PLC, a significant increment in skeletal muscle uptak e of Tc-99m-sestamibi was demonstrated without any apparent change in regional blood flow. This fact, if proven in further studies, may sugg est a role for this tracer as a non-invasive probe of tissue bioenerge tics.