Autonomic regulation involved in the ocular hypotensive action of beta-adrenergic blocking agents.
The effects of racemic propranolol and some related drugs on the intraocular pressure (IOP) were studied after topical application in rabbits. These drugs produced a significant reduction in IOP with the following order of potency: (-)-propranolol greater than timolol greater than (+/-)-propranolol greater than sotalol greater than (+)-propranolol greater than pranolium. Pretreatment of rabbit eyes with atropine significantly antagonized the ocular hypotensive action of (+/-)-propranolol, timolol and pranolium. Both (+/-)-propranolol and timolol produced a significant increase in pupil diameter in the presence of a submydriatic dose of atropine. The activities of monoamine oxidase and carbonic anhydrase were unaffected by (+/-)-propranolol, timolol and pranolium in-vitro. It is concluded from the results that both cholinergic and adrenergic mechanisms may be involved in the ocular hypotensive effects of the drugs.
Alkondon
M
M
Ray
A
A
Sen
P
P
D000319:Adrenergic beta-Antagonists / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002257:Carbonic Anhydrase Inhibitors; D003315:Cornea / Q000187:drug effects; D005260:Female; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D008996:Monoamine Oxidase Inhibitors; D011680:Pupil / Q000187:drug effects; D011817:Rabbits; D013237:Stereoisomerism
D000319:Adrenergic beta-Antagonists; D002257:Carbonic Anhydrase Inhibitors; D008996:Monoamine Oxidase Inhibitors; D001285:Atropine