Connexins in the lens: are they to blame in diabetic cataractogenesis?

The pathohistology of the diabetic lens is an enigma. Under normal conditions the lens behaves as a functional syncitium, whereas the diabetic lens exhibits a localized zone of fibre cell swelling and rupture that is confined to the lens outer cortex. Because the lens fibre cells are extensively coupled by gap junction channels, it is believed that the abnormal closure of these channels is responsible for this phenomenon. New evidence concerning regional differences in gap junction gating supports this contention, and it is used to propose a new hypothesis that may explain the cellular changes observed in the diabetic lens.