Effect of betaxolol on impaired choroidal blood flow after intravitreal injection of endothelin-1 in albino rabbits.
We investigated the effect of topical betaxolol on impaired choroidal blood flow (CBF) induced by endothelin-1 (ET-1) injection into the vitreous of albino rabbits. Betaxolol (n = 7) or balanced salt solution (BSS) (n = 6) was instilled in the right eyes before and 12 hrs after the intravitreal injection of ET-1 (10(-6) M, 10 microl), and BSS was instilled in the right eyes before and 12 hrs after the intravitreal injection of BSS (n = 6). Blood pressure, intraocular pressure and CBF were measured prior to the instillation of betaxolol or BSS, and just before and 2 hrs, 12 hrs and 24 hrs after ET-1 or BSS injection. CBF was measured by scanning laser Doppler flowmetry. Intravitreal injection of ET-1 decreased CBF. Compared with topical BSS, topical betaxolol significantly inhibited the decrease in CBF at 2 hrs (p = .022), 12 hrs (p = .046) and 24 hrs (p = .015) after the intravitreal injection of ET-1. There was no significant change of blood pressure or intraocular pressure after the topical administration of betaxolol or the intravitreal injection of ET-1. The decrease in CBF after the intravitreal injection of ET-1 was partially inhibited by topical betaxolol.
Kim
Jong Hyun
JH
Department of Ophthalmology, Seoul National University Hospital, Korea.
Kim
Dong Myung
DM
Park
Won Chan
WC
D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D015784:Betaxolol / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002829:Choroid / Q000098:blood supply*; D019332:Endothelin-1; D007322:Instillation, Drug; D007429:Intraocular Pressure / Q000187:drug effects; D011817:Rabbits; D012039:Regional Blood Flow / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D019332:Endothelin-1; D015784:Betaxolol