Cellular distribution of alpha B-crystallin in non-lenticular tissues.

alpha B-Crystallin is a subunit of alpha-crystallin, a major protein component of the vertebrate lens. Recently, its expression in various extra-lenticular tissues has been demonstrated by both Western and Northern blotting. In this study, the cellular distribution of alpha B-crystallin in rat organs was examined in detail using immunohistochemistry. Positive reactions were observed in lens, iris, heart, skeletal muscle (type 1 and type 2A fibers), striated muscle in skin and esophagus, Henle's loop and medullary collecting duct of the kidney, Schwann cells of peripheral nerves, glia of the central nervous system, and decidual cells of the placenta. A close correlation with markers of oxidative activity suggests that alpha B-crystallin is expressed in cells that have high levels of oxidative function.