Embryonic Cell Respiration: The Effect of Methylene Blue and 2-4 Dinitrophenol on Embryonic Cell Respiration

The effects of M.b. and 2-4 D.N.P. on the oxygen uptake of mitotically active and blocked grasshopper embryos have been worked out over wide concentration ranges. For both reagents an increase in stimulating effects occurs with increasing concentrations up to a maximum. For M.b. this maximum stimulation continues over a very wide range of concentrations and little injury for exposures of 1 to 2 hours results. With 2-4 D.N.P. rather marked toxic effects occur after the maximum stimulating doses are increased. The relative efficiency of the two reagents is such that 2-4 D.N.P. exerts greater stimulating effects than M.b. at similar concentrations. No evidence has been obtained to indicate any additive effects of the reagents on the oxygen uptake when applied to the cell. Once maximum stimulation has been produced by either compound further additions of stimulating doses of either reagent do not change the result