CHOLERA-TOXIN STIMULATES ADENOSINE-3',5'-MONOPHOSPHATE SYNTHESIS AND EPITHELIAL WOUND CLOSURE IN THE RABBIT CORNEA

  • 1 January 1980
    • journal article
    • research article
    • Vol. 19  (11) , 1321-1327
Abstract
Rabbit corneas were treated in vitro and in vivo with cholera toxin (CTX), a specific and irreversible activator of adenylate cyclase. Tissue pieces incubated in vitro in the presence of 10 .mu.g/ml CTX for 15 min continuously synthesized cAMP at an increased rate for 3 h in the absence of CTX in the medium. Corneas exposed for 10 min to CTX topically in vivo and after various time intervals incubated in vitro had an increased ability to synthesize cAMP for at least 30 h after topical treatment. Epithelial wounds, 6 mm in diameter, were made by brief exposure of corneas in vivo to filter disks soaked in heptanol. Wounds in corneas pretreated with CTX closed at a faster rate and earlier than wounds in corneas pretreated with inactivated CTX. cAMP probably mediates the initial events governing the rate of closure of an epithelial defect.