Stimulation of protein synthesis in dystrophic brain cortex neurons of hypoxia-subjected rats by proliferation-activating protein isolated from nervous tissue of newborn animals.

Hypoxia causes mass diffuse dystrophy of brain cortex neurons, reduces RNA and protein synthesis in neurons and DNA synthesis in the total brain cortex in adult rats. Subsequent transplantation of embryonic nervous tissue (ENT) into the brain of hypoxia-subjected rats normalizes the structure of a considerable part of dystrophic neurons. A protein activator (molecular mass 30,000 D and PI 6.8) was isolated from intensively proliferating cerebellum tissue of newborn rats, dissolved in physiological solution, and injected into one of the hemispheres of hypoxia-subjected rats. The activator significantly stimulated the proliferation of recipient brain cells and normalized the protein biosynthesis in cortical neurons of the recipients like an ENT transplant. Injection into the brain of hypoxia-subjected rats of a physiological solution alone does not produce such an effect. The presented results have been obtained by the methods of autoradiography and biochemistry using 3H-leucine for estimating the intensity of protein synthesis by its incorporation into cells.