Effect of low concentrations of cyanide on SLO , of tissue slices ’

FERNANDEZ F., ADOLFO, JORGE GONZALEZ-QUINTANA, AND A~AURICIO RUSSEK. E$ect of low concentrations of cyanide on Qo2 of tissue slices. Am. J. Physiol. 204(2) : 314-316. 1 g63.The oxygen consumption of brain, liver, and kidney slices measured in the Warburg apparatus was not significantly depressed by concentrations of sodium cyanide of 0.2, 0.5, and 2 pg/ml. This last concentration is considered equal to that attained in the blood after an injection of 0.2 mg/kg, which produces remarkable in vivo effects described elsewhere. Therefore, the effects obtained in vivo cannot be due to the depression of tissue respiration by cyanide, but are probably caused by the stimulation of chemoreceptors. A concentration of 5 pg/ml notably reduced the Qoz of brain slices, and IO pg/ml reduced that of all three tissues. As reported by others, 50 pg/ml reduced the Qoz of kidney slices by 807~. It is noteworthy that 0.2 pg/ml of NaCN produced a 407~ increase (P < 0.01) in the Qoa of liver slices but only a 5-13 Y0 increase, not statistically significant, in brain slices.