The effect of timolol maleate on the disruption of the blood-aqueous barrier in the rabbit eye.
A disruption of the blood-aqueous barrier in rabbit eyes was elicited by use of topical prostaglandin E2(PGE2), infrared irradiation of the iris, or by subcutaneous alpha-melanocyte-stimulating hormone (alpha-MSH). The aqueous flare provoked was measured quantitatively with a photoelectric instrument. The effect of the (topical) beta-adrenergic antagonist timolol maleate on the breakdown of the blood-aqueous barrier was tested. Timolol applied topically in very large doses had no effect on exogenously administered PGE2. However, even in a very small concentration applied topically, timolol reduced the flare response to both infrared irradiation and alpha-MSH. These results support the theory that the effect of alpha-MSH and infrared irradiation on the blood-aqueous barrier is dependent on intact beta-adrenergic receptor sites.
D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001082:Aqueous Humor / Q000187:drug effects*; D005123:Eye / Q000187:drug effects* / Q000528:radiation effects; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology*; D011458:Prostaglandins E / Q000494:pharmacology; D011817:Rabbits; D013999:Timolol / Q000097:blood / Q000494:pharmacology*
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011458:Prostaglandins E; D013999:Timolol; D009074:Melanocyte-Stimulating Hormones