CIRCADIAN AQUEOUS FLOW-MEDIATED BY BETA-ARRESTIN INDUCED HOMOLOGOUS DESENSITIZATION

It was hypothesized that homologous desensitization regulates signal t ransduction from the beta-adrenergic receptor in the ocular ciliary ep ithelium to affect the circadian rhythm of aqueous humor secretion. be ta-arrestin-1 was cloned from the rabbit ciliary epithelium, and the f ull length cDNA used as a probe for Northern blot analysis to examine the diurnal expression of beta-arrestin mRNA. Protein expression of be ta-arrestin-1 at intervals during the circadian cycle of aqueous secre tion showed a decrease in beta-arrestin expression when maximal activa tion of the beta-adrenergic receptor is known to increase secretion. D iurnal expression of beta-arrestin suggests that homologous desensitiz ation can regulate the circadian rhythm of aqueous now. (C) 1997 Acade mic Press Limited.