GENDER DIFFERENCE IN THE CONCENTRATION OF THE ANTIOXIDANT URIC-ACID IN HUMAN NASAL LAVAGE

The entire respiratory tract is continually exposed to a variety of ox idants, of which a large percentage may react within the nasal passage s. In the secretions lining the human nasal cavity uric acid has been shown to be the only low molecular weight antioxidant present in abund ance. Because this uric acid originates in the plasma, it is possible that factors affecting the levels of plasma uric acid will also alter the levels recovered in lavage fluids. Lavage fluid from 15 men (20-68 years) and 11 women (20-59 years) were collected using a modified Fol ey catheter which allowed each subject to supply a basal lavage (salin e removed immediately after instillation) and an 'accrued' lavage (sal ine left in situ for 5 min) from each nasal cavity. Lavage fluids were assayed for protein, lysozyme acid uric acid. The levels of protein a nd lysozyme in the recovered fluids were found not to be affected by s ubject age or gender. Uric acid, however, was found to have a weak neg ative (r(2) = -0.685 basal and -0.62 accrued) correlation with age in women, but no such correlation was noted in men. Also, the levels of u ric acid in women (1.3 +/- 0.3 mu M/L basal and 4.5 +/- 0.6 mu M/L acc rued) were found to be lower than those seen in men (3.1 +/- 0.6 mu M/ L basal and 8.4 +/- 1.3 mu M/L accrued) (p = 0.0681 and 0.0394 respect ively). It is concluded that women have lower levels of uric acid in l avage fluids than men, with subject age also possibly affecting lavage uric acid. It is also proposed that such factors which lead to decrea sed levels of uric acid may be related to individual sensitivity to in haled oxidants such as ozone.