Compounds were added 15 min prior to Cys addition, and cyt capacity was determined after 4 h. Compounds were used at the following concentrations: Cys (1mm), endothall (100 μm), ruthenium red (100 μM), flavone (1 mm), cycloheximide (360 μm), and LaCl (1 mm). Data are the mean ± se from three to five independent experiments. The untreated (control) cells had a cyt capacity of 1,132 ± 62 nmol O₂ mg⁻¹ dry wt h⁻¹ (mean ± se).