GLUTATHIONE-CONTROLLED ANAEROBIOSIS IN CRYPTOCERCUS, AND ITS DETECTION BY POLAROGRAPHY ,

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Abstract
1. Polarography, employing a mercury-dropping electrode and an electrolysis vessel for analysis of sample slightly less than 0.1 ml., was applied in this study. 2. Polarograms of Cryptocercus hind-gut content lack an oxygen wave and indicate absence of dissolved oxygen to the extent of apparatus sensitivity (10-6M). 3. A single polarographic wave registers a half-wave potential approximating -0.2 volt vs. S.C.E. within a 0- to -0.4-volt span. Specificity of this method enabled identification of reduced glutathione (7.2 x 10-4M) following comparative inspection of numerous reducing agents. Supplementary assays using sodium nitroprusside, alloxan monohydrate, and Hydra confirmed the presence of reduced glutathione in hind-gut content. 4. Flagellate protozoa, symbionts in the hind-gut fluid of Cryptocercus, represent the site of glutathione synthesis. 5. Prolonged oxygen passage through hind-gut samples (0.1-0.5 ml.) fails to alter polarograms with respect to negative pO2 registration, but reduced glutathione concentration is decreased in direct proportion to oxygen exposure intensity. 6. Partial restoration of reduced glutathione concentration following nitrogen gas passage through samples moderately exposed to oxygen cannot be explained. 7. Brief atmosphere contact with heat-altered hind-gut samples results in polarograms showing PO2 2 contamination and an absence of reduced glutathione. Until enzyme analyses are completed, sample alteration by heat merely suggests presence of a mechanism for glutathione maintenance in the reduced state. 8. Cryptocercus hind-gut content is anaerobic to the extent of maximal physical and chemical maintenance as are the microorganisms normally living within it. Reduced glutathione is considered of major importance in this role. 9. Some evidence exists which may support Calvin's hypothesis for addition of mercaptans across carbonyls in a biological sample. The value of such a mechanism to Cryptocercus and its symbionts is theorized.