Regional differences in effects of hypoxia and hypokinesia upon neuronal and neuroglial RNA content in rat spinal cord.

By means of two-wavelength ultraviolet cytospectrophotometry a marked RNA accumulation was revealed in the cytoplasm of motoneurons of lumbar intumescence of the rat spinal cord after 3-week-long hypoxia or hypokinesia as well as their combination. In the neuroglial cells adjacent to these motoneurons, both hypoxia and hypokinesia resulted in a reduction of the total RNA amount per cell while combined effect of both stress-factors brought about an increase in the RNA content. In cervical intumescence motoneurons and in their perineuronal glia, no changes in the RNA content were revealed after single or combined effects of prolonged hypoxia and hypokinesia, with the only exception of glial cells in which a pronounced increase in the RNA content was detected at the hypoxia plus hypokinesia combination. Morphological and functional heterogeneity of the nerve tissue is discussed with respect to metabolic responses of various kinds of neurons and glial cells to stress-factors.