Beta-adrenergic responsiveness of choroidal vasculature.
Using in vitro binding methods and autoradiographs, the authors showed that choroidal vessels specifically bind iodine 125 cyanopindolol, a nonselective blocker of beta-adrenergic receptors, in albino rabbits. In humans, the presence of beta-adrenergic receptors in choroidal vessels was confirmed by showing an increased choroidal vascular tone after systemic administration of timolol maleate, a nonselective beta-adrenergic blocker. Topically administered timolol maleate lowered the intraocular pressure but did not reach the choroidal receptors in sufficient quantity to produce a measurable effect on vascular tone.
Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, FL 33101.
A L
AL
Grajewski
G
G
Ferrari-Dileo
W J
WJ
Feuer
D R
DR
Anderson
D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000378:metabolism; D000328:Adult; D000818:Animals; D001345:Autoradiography; D002829:Choroid / Q000098:blood supply* / Q000378:metabolism*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D012171:Retinal Vessels / Q000378:metabolism*; D013999:Timolol / Q000008:administration & dosage
D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; C047975:cyanopindolol; D013999:Timolol; D010869:Pindolol