AIM: To study the effects of estrogen on the expression of matrix metalloproteinases-1(MMP-1)and tissue inhibitor of matrix metalloproteinase-1(TIMP-1)in lacrimal gland of ovariectomized rat.

METHODS:A total of 60 female rats were examined for the expression of MMP-1 and TIMP-1 protein in lacrimal gland through SⅠt measurement together with Western- blot and RT-PCR methods.

RESULTS:There was significant reduction in SⅠt and increase in the protein expression of MMP1, TIMP1 and mRNA after ovariectomy conducted on rats(P<0.05). After estrogen treatment, there was significant reduction in SⅠt and increase in the expression of MMP1, TIMP1 and mRNA as compared with before treatment(P<0.05).

CONCLUSION: Estrogen must be applied cautiously to treat xerophthalmia following menopause because estrogen can up regulate the expressions of MMP-1 and TIMP-1 and can aggravate the decrease of lacrimal secretion.