Prolactin may stimulate proliferation in the olfactory epithelium of the female mouse

Background: Although it is well known that olfactory receptor neurons differentiated from stem cells have an unusual lifelong ability to continue neurogenesis, effective treatment of patients with sensorineural olfactory loss is still lacking. The purpose of this study was to determine whether intranasal prolactin (PRL) is an effective inducer of proliferation in the olfactory epithelium (OE). Methods: The OE of mice treated with PRL for 6 consecutive days and of pregnant mice on gestation day (GD) 7 was investigated by immunohistochemical study using antibodies to bromodeoxyuridine. Results: The number of bromodeoxyuridine -labeled cells in the OE increased significantly in PRL-treated female mice and GD 7 mice (but not PRL-treated male mice) compared with controls. Conclusion: Pregnancy may induce proliferation in the OE, and administration of intranasal PRL may have almost the same effect as pregnancy on the OE of female mice.