Subcellular Particles in Tumors-V. Behavior of Mitochondria of Hepatoma HC and Morris Hepatomas 7316A, 7794B and 16 in Density-Gradient Centrifugation

Document Type

Article

Publication Date

1-1-1972

Description

1. (1) The distribution of mitochondrial enzymes has been investigated after isopycnic centrifugation of mitochondrial fractions of HC hepatoma and Morris hepatomas 7794B, 7316A and 16. Two kinds of density gradient were used, one consisting of glycogen dissolved in aqueous sucrose of different molalities and the second of aqueous sucrose alone. 2. (2) In sucrose gradient experiments, the distributions of cytochrome oxidase, monoamine oxidase and glutamate dehydrogenase were established. Isopycnic centrifugation was performed at two speeds, 39,000 rev/min and 65,000 rev/min. At 39,000 rev/min, a similar distribution was seen for the three enzymes in each hepatoma; however, the distribution exhibited marked differences from one hepatoma to the next. The distributions of the three mitochondrial enzymes of hepatomas 16 and HC remained practically unchanged when centrifugation was performed at 65,000 rev/min instead of 39,000 rev/min. In contrast, the higher centrifugation speed did induce changes in the distributions of hepatoma 7316A and 7794B enzymes. 3. (3) In glycogen gradient experiments, cytochrome oxidase distribution was studied. The distribution indicates that the behavior of mitochondria of hepatoma 7794B, 7316A and HC in such gradients is qualitatively similar to that of rat liver mitochondria. However, the parameters that characterize the intramitochondrial spaces, calculated from the distribution pattern, differ to a variable extent from those calculated for rat liver particles. The cytochrome oxidase of hepatoma 16 behaves as if the mitochondria of this tumor were devoid of an osmotic space.

Link to Full Text

Share

COinS