Oxygen consumption and luminescence of Porichthys photophores stimulated by potassium cyanide.

Isolated photophores of Porichthys notatus, maintained in saline at 20 degrees C, do not luminesce and show an oxygen consumption rate of 0.07 +/- 0.01 nmol min-1 photophore-1. In the presence of 10(-6) M-KCN, the photophores do not luminesce but the resting respiration decreases by about 50%. In the presence of 10(-5) M-KCN, some photophores do not luminesce and their respiration rate decreases by about 75%. Others show a response and resting oxygen consumption slowly increases. At high concentration (10(-4) and 10(-3)M), KCN induces a large light emission and increase in oxygen consumption. The stimulatory effect of KCN on the photophore oxygen consumption is tentatively explained by an activation of the luciferin-luciferase system by calcium ions.