THE OXIDATIVE METABOLISM OF EGGS OF URECHIS CAUPO

Abstract

1. The respiration and normal development of fertilized eggs of Urechis caupo are inhibited by low concentrtaions of HCN, 5 x 10-6 M. Known concentrations of HCN were established within the manometer flasks by the use of Ca(CN)2-Ca(OH)2 mixtures in the center-wells, with and without the appropriate amounts of NaCN in the egg suspensions.2. The respiration of fertilized eggs was photo-reversibly inhibited by 95% CO in O2. The inhibition of development was not so marked at this tension as in the cyanide experiments.3. CO markedly stimulated the respiration of the eggs in the light. The occurrence of a similar action in the dark is presumed to account for the moderate degree of depression of respiration by CO in the dark.4. Spectroscopic examination of the eggs at the temperature of liquid nitrogen revealed absorption bands at 551 mµ and 580-590 mµ. Absorption bands at these wave-lengths are associated with the presence of cytochromes c and a.5. An egg brei rapidly oxidized reduced cytochrome c, but intense ...