EFFECTS OF ADRENERGIC-DRUGS ON INTRACELLULAR ELECTRICAL POTENTIAL DIFFERENCE OF RABBIT CILIARY EPITHELIAL-CELLS

The effects of adrenergic drugs on intracellular electrical potential difference (PD) of rabbit ciliary epithelial cells were investigated. Epinephrine as well as norepinephrine hyperpolar-ized the PD at lower concentrations (10-6 M) and depolarized the PD at higher concentrations (>10-5 M). Isoproterenol produced a depolarization of PDI and phenylephrine caused a hyperpolar-ization only. After pretreatment with propranolol, the change of PDI by isoproterenol was minimal. Selective agonists and antagonists were used to further characterize adrenergic effects on the PDI. Both beta1, and beta2 agonists caused a depolarization of PDI while both beta2. and beta2 antagonists produced a hyperpolarization. Alpha1, antagonist depolarized the PDI and alpha2 antagonist hyperpolarized the PDI. Such electrophysiological effects of the adrenergic drugs confirm the presence of alpha and beta adrenoceptors in the rabbit ciliary epithelial cells. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.