title: Delay of cataract development in the Shumiya cataract rat by the administration of drinking water containing high concentration of magnesium ion.
abstract: We discovered that the cataract development in the Shumiya cataract rat (SCR) can be prevented by the administration of deep-sea drinking water (DDW). A standard diet based on the American Institute of Nutrition guidelines (AIN-76) and DDW containing a high mineral concentration such as low, medium and high Mg2+ content (50, 200 and 1000 mg of Mg2+/l, respectively) were used in this study. SCRs were freely fed with combinations of the standard diet and purified water or DDW during 5-15 weeks of age. The opacities of SCR lenses were documented by anterior eye segment analysis system EAS-1000. The onset of opacification of cataractous SCR lenses administered a combination of standard diet and purified water started at 11 weeks of age, and mature cataracts had formed at 13 weeks of age. However, the supplementation of Mg2+ by administration with medium DDW showed the greatest effect of delay of cataract onset in SCR. In addition, even cataractous SCR lenses at 14 weeks of age showed differences in opacity level. The opacification and Ca2+ of the lenses in cataractous SCR administered medium DDW were lower than those administered purified water. In conclusion, the present study demonstrates that administration of DDW potently delays cataract development in SCR, and this may be caused by inhibiting the increase in Ca2+ levels in the lens.
authors.affiliation: School of Pharmacy, Kinki University, Higashi-Osaka, Osaka, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Nagai
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Ito
authors.forename: Mitsushi
authors.initials: M
authors.lastname: Inomata
authors.forename: Seigo
authors.initials: S
authors.lastname: Shumiya
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tai
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Hataguchi
authors.forename: Koji
authors.initials: K
authors.lastname: Nakagawa
mesh_terms: D000818:Animals; D002118:Calcium / Q000097:blood / Q000378:metabolism; D002386:Cataract / Q000097:blood / Q000175:diagnosis / Q000378:metabolism / Q000517:prevention & control*; D004195:Disease Models, Animal; D004326:Drinking; D007421:Intestine, Small / Q000378:metabolism; D007908:Lens, Crystalline / Q000187:drug effects* / Q000378:metabolism; D008274:Magnesium / Q000097:blood / Q000378:metabolism; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014018:Tissue Distribution; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D008278:Magnesium Sulfate; D008274:Magnesium; D002118:Calcium