Volume Increase in Rat Adrenocortical Mitochondria by Single ACTH Administration. A Stereological Study

抄録

Bach's theory on sphere size distribution has been applied to the quantitative analysis of changes in the mitochondrial population of the parenchymal cells in the zona fasciculata of the rat adrenal cortex at one hour after a single dose (4 I. U. per head) of ACTH administration. The three-dimensional reconstruction of the mitochondrial population has been performed on the data on diameters of the electron microscopic profiles of the mitochondria sampled at random. The volume for an averaged mitochondrion was 0.617μ³ in the intact control and was significantly increased in the ACTH-injected rats amounting to 0.841μ³. The size distribution histograms for the reconstructed mitochondrial population revealed a shift of mitochondria in the ACTH-injected rats to the larger. These quantitative stereological computations have clearly shown that there is a volume increase in those mitochondria referred to above under the influence of ACTH within one hour. Possible significance of the present findings has been discussed.