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The Response of Ornithine Decarboxylase During Neuronal Degeneration and Regeneration in Olfactory Epithelium
Author(s) -
Rochel S.,
Margolis F. L.
Publication year - 1980
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1980.tb07082.x
Subject(s) - olfactory epithelium , ornithine decarboxylase , olfactory bulb , olfactory tubercle , population , olfactory mucosa , endocrinology , biology , medicine , olfactory nerve , olfactory ensheathing glia , regeneration (biology) , olfactory system , microbiology and biotechnology , chemistry , neuroscience , central nervous system , biochemistry , environmental health , enzyme
Abstract: Mature olfactory neurons are continually replaced from a population of progenitor cells. Olfactory nerve section, bulbectomy, or treatment with certain chemicals induces degeneration of olfactory neurons followed in some cases by regeneration. Ornithine decarboxylase (ODC) activity was measured in mouse olfactory tissues as an indicator of cellular regeneration. ODC activity in olfactory tissue (0.2–0.4 nmol/mg protein/h) is 10‐30 times higher than in a variety of other cerebral tissues. Within 3 h after unilateral olfactory nerve section, ODC activity in the epithelium declines to 50% of control followed by a slow return to basal activity by 6 days. In the same animals, ODC activity increases severalfold in bulb (1 day) with a gradual decline to normal (9 days). Except for an early transient increase, the effects of unilateral bulbectomy on epithelial ODC activity are similar to those seen after nerve section. The changes in ODC activity following intranasal irrigation with 10 m m ‐colchicine also closely mimic those seen after nerve section. The effects of intranasal irrigation on ODC activity with 0.5% Triton X‐100 or 0.17 m ‐ZnSO 4 are more complex. Thus, when the mature neuronal population is degenerating after surgery or chemical treatments, ODC activity decreases in the epithelium. The subsequent increase of ODC activity prior to reconstitution of the mature neuronal population probably reflects the regeneration mechanism of the olfactory epithelium. The increase of ODC activity in the olfactory bulb after nerve section is best interpreted as a cellular injury response. These alterations in ODC activity in olfactory tissues after chemical and surgical treatments constitute the earliest biochemical events observed in these tissues in response to cellular damage.