NARCOSIS AND CELL DIVISION IN COLPODA STEINII

¹ Arnold Biological Laboratory, Brown University, Providence, R. I.

1. Ethyl carbamate has been demonstrated to be effective in inducing aberrant nuclear behavior during division of the ciliate Colpoda steinii. This activity is shared by other carbamates and chloral hydrate. These effects are described in detail.

2. A quantitative means of assaying cytologically the activity of these substances is described. On the basis of defective polar movement of daughter micronuclei ethyl carbamate was found to be more active than chloral hydrate. A possible explanation for this observation is postulated.

3. The results of preliminary work involving treatment of dividing cells with potassium cyanide, potassium ferricyanide, arsenite, and iodoacetate are reported. These agents apparently do not share the activity evidenced by the carbamates or chloral hydrate.

4. By means of the Warburg technique the effect of urethane and chloral hydrate on respiration of C. stenii was studied.

5. Discontinuity in the quantitative action of these agents on respiration is interpreted to indicate the existence of at least two fractions of metabolism. One of these, the activity system, is believed to be associated with the process of cell division.

6. Complete separation of these two systems is not considered probable, however, and caution is urged in the interpretation of discontinuity in Mass Action treatment of this and similar data.

7. The significance of the association of the appearance of aberrant division figures, growth inhibition and discontinuity in the relationship of narcotic concentration to respiratory inhibition is pointed out. Discrepancies in these relationships are discussed.

8. The bearing of metabolic inhibition on the general problem of the pathology of mitosis is discussed.