Testis respiration rate after fly exposure under hypomagnetic and microgravity conditions. (A) V0, respiration rate of permeabilized cells; (B) Vglu + mal, respiration rate after adding 10 mM glutamate + 5 mM malate; (C) Vmax, maximum respiration rate after adding 2 mM ADP; (D) V(II), respiration rate after adding 0.5 μM rotenone (complex I inhibitor) and the subsequent supplement 10 mM succinate (substrate of complex II); (E) V(IV), respiration rate after adding 5 μM antimycin (complex III inhibitor) and the subsequent supplement 0.5 mM TMPD + 2 mM ascorbate (artificial substrates of complex IV). * p < 0.05 compared with the corresponding control group.