Morphological studies on cataract and small lens formation in neonatal rats treated with monosodium-L-glutamate.

Changes in the transparency and size of lenses in rats were investigated following administration of monosodium-L-glutamate (MSG). MSG (5 mg/g b.w.) was injected subcutaneously on the 9th and 10th day after birth. Ophthalmoscopically, localized opacity was apparent at the posterior pole of the lens corresponding to the attached site of the hyaloid vessels at the 1-month stage. The incidence of cataract increased with age, reaching more than 75% at 4 months. Morgagnian globules were histologically detected in the opacity of the posterior lens cortex. The size and weight of the lens were smaller than those of the control rats. These findings indicate that the administration of MSG could be an etiologic factor in cataract formation in the developing rat.