title: Increased Expression of Interleukin-18 in Lenses of Ovariectomized Rats.
abstract: Previous studies showed an increased prevalence of cataracts in postmenopausal women. In this study, we investigated changes in the levels of calcium ion (Ca(2+)) and interleukin (IL)-18, which are factors in cataract development, in the lenses of ovariectomized (OVX) rats, a model of postmenopausal woman. Although the Ca(2+) content in the blood of OVX rats increased 1 month after ovariectomy and subsequently decreased, the Ca(2+) content in the lenses was unchanged in OVX rats 1-3 months after ovariectomy. The Ca(2+)-ATPase activity in the lenses of OVX rats peaked 1 month after ovariectomy, and the behavior of Ca(2+)-ATPase activity in lenses of OVX rats was similar to that of the Ca(2+) concentration in the blood. It is possible that hypercalcemia increases the Ca(2+) inflow into the lens; however, the enhanced Ca(2+)-ATPase activity prevents the Ca(2+) level from rising. On the other hand, we found that the levels of both IL-18 and interferon (IFN)-γ in the lenses of OVX rats were significantly increased as compared with the lenses of sham (control) rats during the period 1-3 months after surgery. These results suggest that the expression of IFN-γ via IL-18 in the lenses of OVX rats is induced by ovariectomy, and that excessive IL-18 and IFN-γ production in the lenses may be related to cataract development in postmenopausal women. These findings support those of previous studies that assessed lens opacification in postmenopausal women.
authors.affiliation: Faculty of Pharmacy, Kinki University.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Nagai
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Ogata
authors.forename: Naohito
authors.initials: N
authors.lastname: Kawasaki
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Ito
mesh_terms: D000818:Animals; D015519:Bone Density; D002118:Calcium / Q000097:blood / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D020382:Interleukin-18 / Q000235:genetics / Q000378:metabolism*; D007908:Lens, Crystalline / Q000378:metabolism*; D010052:Ovariectomy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D053724:Receptors, Interleukin-18 / Q000235:genetics / Q000378:metabolism
chemical_list: D020382:Interleukin-18; D012333:RNA, Messenger; D053724:Receptors, Interleukin-18; D007371:Interferon-gamma; D002118:Calcium