Respiration rate of rat-liver cells at low oxygen concentrations

Abstract

A method is described for following the respiration rate [QO2(N)] polarographically on a suspension of cells. Oxygen is replaced without introducing it into the polarographic cell by keeping a part of the suspension together with O2 in syringes attached to the cell. There was a rapid decrease in respiration rate from the maximum. The plot of v/v max. -v against log (oxygen concentration) was not linear at higher respiration rates. Between 1.4 and 40[degree]C, the energy of activation was 16,000 cals. The deviation from linearity at high respiration rates is due to another component of the succinic oxidase system being limiting, above 80% saturation of the respiratory enzyme. Similar results were obtained with mitochondria.