Aliquots (100 μL) of this solution and of the incubation media were used for radioactive counting in scintillation liquid (5 mL): toluene–Triton X-100 (2:1, v/v) PPO 0.4%–POPOP 0.01%. The results were expressed as tissue/medium (T/M) ratio, i.e., dpm/mL of tissue fluid divided by dpm/mL of incubation medium.