Heme oxygenase-2 immunoreactivity in developing and mature bovine olfactory epithelium

In the present study the localization of heme oxygenase-2 (HO-2) in developing and mature olfactory epithelium of the bovine is investigated using immunohistochemistry and post embedding immunogold labelling. HO-2 immunoreactivity is first seen in epithelial cells localized along the luminal surface of the olfactory pit. Up to midgestation the number of HO-2 immunoreactive cells increases throughout all layers of the developing olfactory epithelium. From midgestation through adulthood immunostaining is restricted to perinuclear cytoplasm and axons of mature olfactory receptor neurons localized in intermediate epithelial regions. The temporal and spatial expression patterns of HO-2 immunohistochemistry support the notion that CO plays a role in neuronal differentiation while its presence in mature neurons might be functionally related to olfactory transduction.