The olfactory organ is one of the chemosensory organs and the olfactory receptor cell is bipolar cell which has one axon and one dendrite. The olfactory neuron unlike most nouron in other nervous system, might be directly exposed to airborn
chemicals
and so creates vulnerability to bacterial and viral invasions and the toxic effects of environmental polluants. Despite of these. the olfactory cells have the capacity to turnover and to be replaced after injury.
The olfactory epithelium of vertebrates consists of three basic cell types: olfactory receptor cell, basal cell and supporting cell, the derivation of each of the three cell types of the olfactory epithelium is still a matter of discussion. It
was
reported that the stem cell of the olfactory cell might be basal cell. Bowman's gland cell, interstitial cell and blastemzellen. But recent studies have shown that the olfactory cell originates from basal cell by using autoradiographic technique.
However, an autoradiographic method requires special isotope institute, protection from the exposure of radiation hazard and it takes a long time for the final specimen to observe.
Recently, a rapid technique whithout using the radioisotope has been alternatively developed in which a thymidine analogue. 5-bromo-2-deoxyuridine (BrdU). is incorporated into replacing DNA and subsequently localized using a specific monoclonal
antibody
and uses in the quantitative study of tumor cells clinically. But there is few reports to study on the olfactory cell kinetics using this technique.
Therefore, author studied the origin of the olfactory cell and the turnover of olfactory epithelium by means of immunohistochemical technique using anti-BrdU antibody in normal and 1% ZnSO4-treated mice after injection of BrdU. The BrdU labeled
cells
were observed from 1 hour to 26 days after injection of BrdU, not in 30 days, At 1 hour after BrdU injection, the labeled cells were concentrated in the basal cells and at 7 days after 1% ZnSO4 treatment the labeled cell were located from the
basal
cell
layer to upper part of the olfactory epithelium.
The above findings suggest that basal cells are the stem cells of the olfactory receptor cells and the period of turnover in the olfactory mucosa in mice may be within 30 days. And the immunohistochemical technique using anti-BrdU antibody is
useful for
the observation of the cell kinetics of the olfactory epithelium
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