Effect of tunicamycin on histological organization and Na, K-ATPase distribution in the adult cat retina.

Intravitreal injection of tunicamycin (TM) was evaluated as a method for inducing photoreceptor-specific degeneration in cat retina. TM (1 microg, 5-weeks duration) markedly decreased electroretinogram amplitudes. A polyclonal antibody directed against the Na, K-ATPase was used to further assess cell-specific retinal injury induced by TM. TM-treatment induced marked alterations in the differential distribution of the Na, K-ATPase within the retina. Histology confirmed photoreceptor degeneration in TM-treated retina, but further showed a severe, non-selective degradation of most retinal layers. Therefore, long-term intraocular exposure to TM results in a progressive general toxicity to the cat retina.