EXPRESSION OF NA+ MYO-INOSITOL COTRANSPORTER MESSENGER-RNA IN NORMAL AND HYPERTONIC STRESS RAT EYES/

We studied the localization of Na+/myo-inositol cotransporter (SMIT) m RNA in normal and hypertonic stress rat eyes by in situ hybridization histochemistry using cRNA probes. SMIT mRNA signals were observed in t he iris-ciliary body, the lens epithelial cells, and the ganglion cell layer and the inner nuclear layer of the retina. There was a rapid in crease on SMIT mRNA in the retina of hypertonic stress rats compared w ith control rats. These findings suggest that Na+/myo-inositol cotrans porter gene expression is osmotically regulated in vivo to protect ret inal neuronal function against hypertonic stress.