Circadian aqueous flow mediated by β-arrestin induced homologous desensitization

Abstract

It was hypothesized that homologous desensitization regulates signal transduction from the beta-adrenergic receptor in the ocular ciliary epithelium to affect the circadian rhythm of aqueous humor secretion. β- arrestin-1 was cloned from the rabbit ciliary epithelium, and the full length cDNA used as a probe for Northern blot analysis to examine the diurnal expression of β-arrestin mRNA. Protein expression of β-arrestin-1 at intervals during the circadian cycle of aqueous secretion showed a decrease in β-arrestin expression when maximal activation of the β-adrenergic receptor is known to increase secretion. Diurnal expression of β-arrestin suggests that homologous desensitization can regulate the circadian rhythm of aqueous flow.