Biochemical characterisation of mitochondrial and lysosomal particles in foetal and neonatal rats

1. The sedimentation coefficients of the mitochondria are larger in the foetal as compared to the adult rats. For cytochrome oxidase, the values are respectively 18.700 x 10(3) and 13,550 x 10(3) S. 2. Lysosomal sedimentation coefficients are smaller in the foetal as compared to the adults. For beta galactosidase, the values are respectively 5.090 x 10(3) and 10.430 x 10(3) S. 3. It is concluded that the mitochondria are larger and the lysosomes smaller in size in the foetus as compared to the adults. 4. The external membrane of neonatal mitochondria and the membrane of foetal and neonatal lysosomes are more resistant to osmotic swelling.