OXYGEN POISONING IN THE ANNELID TUBIFEX TUBIFEX. II. OSMOTIC PROTECTION

¹ Department of Physiology and Biophysics, University of Illinois, Urbana, Illinois 61801

1. One per cent glucose when present during oxygen exposure provided significant protection of T. tubifex from doses which resulted in high worm mortality.

2. Glucose protection was not reversed by 2,4-dinitrophenol; 2,4-dinitrophenol was itself protective.

3. Sodium chloride at a concentration osmotically equivalent to one per cent glucose provided protection equal to or better than that of glucose.

4. Proteose-Peptone, CaCl₂, KC1, CoCl₂, MnCl₂ and NaNO₃ also provided various degrees of protection when they were present during oxygen exposure.

5. The solute concentration providing maximum protection against oxygen poisoning had an optimum at a concentration osmotically equivalent to one per cent glucose.

6. Sodium chloride increased the survival of oxygen-exposed T. tubifex even when it was added as long as 12 hours after oxygen treatment.

7. Sodium chloride provided at least partial protection against the stress of heating or hydrogen peroxide exposure.