INFLUENCE OF CYANIDE AND LACK OF OXYGEN ON THE ACTIVATION OF STARFISH EGGS BY ACID, HEAT AND HYPERTONIC SEA-WATER

¹ From the Marine Biological Laboratory, Woods Hole and the Laboratory of General Physiology, University of Chicago

1. Suppression of oxygen-consumption in freshly removed unfertilized starfish eggs (by exposure to cyanide-containing or oxygen-free sea-water) prolongs by several hours the period during which they remain responsive to artificial activation by heat, acid, or hypertonic sea-water (as well as to sperm fertilization). The possible interval between a first partial and a second completing activation may be similarly prolonged.

2. During the exposure of the eggs to these asphyxiating conditions their susceptibility to activation by heat or acid, as indicated by the effective durations of exposure, undergoes a progressive increase.

3. Eggs kept for some hours in cyanide-containing or oxygen-free sea-water and then exposed to acid or heat while immersed in these media show normal activation. On the other hand, a similar suppression of oxygen consumption prevents activation by hypertonic sea-water.

4. It is suggested that the activation by hypertonic sea-water depends on the increased intracellular production, by dehydrolytic synthesis, of some complex specific compound (e.g., protein); while in the anaërobic activation by acid (or heat) the critical change is a hydrolysis (e.g., of a phosphagen compound), yielding a product which combines with the complex compound to form the specific activating substance. The accumulation of this substance to a certain definite level determines activation. Two metabolic processes, respectively aërobic and anaërobic, would thus coöperate in activation. The fact that either hypertonic sea-water or acid (or heat), acting alone, can produce the same physiological end-effect, complete activation, is shown to be consistent with this hypothesis.