Relationship between RNA polymerase I activity and ornithine decarboxylase in rat liver tissues

Distribution patterns of ornithine decarboxylase in cells and tissues: facts, problems, and postulates

Ornithine decarboxylase (ODC) is a key enzyme in polyamine biosynthesis. Increased polyamine levels are required for growth, differentiation, and transformation of cells. In situ detection of ODC in cells and tissues has been performed with biochemical, enzyme cytochemical, immunocytochemical, and in situ hybridization techniques. Different localization patterns at the cellular level have been described, depending on the type of cells or tissues studied. These patterns varied from exclusively cytoplasmic to both cytoplasmic and nuclear. These discrepancies can be partially explained by the (lack of) sensitivity and/or specificity of the methods used, but it is more likely that (sub)cellular localization of ODC is cell type-specific and/or depends on the physiological status (growth, differentiation, malignant transformation, apoptosis) of cells. Intracellular translocation of ODC may be a prerequisite for its regulation and function.

RNA transcription in axotomized dorsal root ganglion neurons

Levels of RNA transcription were examined in L5 sensory ganglion neurons after unilateral crush injuries of the sciatic nerve using an in situ autoradiographic technique. Neuronal transcription increased in a biphasic pattern on the lesioned side within the first two weeks after injury. The timing and pattern of increases in transcription corresponded to previously reported increases RNA synthesis. The data demonstrate a dynamic regulation of RNA transcription in regenerating neuronal populations. This technique may prove to be useful in the study of factors controlling transcriptional activity in injured neurons.