RESUMO
Objective To investigate the expression of MUC5AC in human sinus mucosa and compare the expression of MUC5AC mRNAs in normal and chronic sinus mucosa. Methods Thirty two chronic ethmoid sinusitis mucosa samples and 7 normal ethmoid sinus mucosa samples were used. The protein expression of MUC5AC was examined by using immunohistochemical method. RNAs were extracted from sinus mucosa, and fluorescent quantitative nested RT-PCR was performed for MUC5AC. Results The mean gray scale of MUC5AC protein expression was 159. 72 ± 14. 14 in chronic ethmoid sinusitis mucosa and 115.80 ±31.58 in normal ethmoid sinus mucosa. There was significantly different between two groups (t =3.57, P ＜0.01). The levels of MUC5AC mRNAs in chronic rhinosinusitis [(35.80 ± 19. 74) × 105copies/μg] were higher than those in normal sinus mucosa [(4. 66 ± 2. 47) × 105 copies/μg] . M UC5 AC mRN A expression had significant difference between chronic ethmoid sinusitis mucosa and normal sinus mucosa(t =4. 12, P ＜0.01). Conlusion This result suggested that up-regulation of MUCSAC in chronic rhinosinusitis might play an important role in the pathogenesis of sinus hyperesecretion in chronic rhinosinusitis.