Effects of adenosine on ocular blood flow

• Published in: Investigative ophthalmology & visual science Vol. 36; no. 9; pp. 1904 - 1909
• Main Authors: Portellos, M, Riva, CE, Cranstoun, SD, Petrig, BL, Brucker, AJ
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01.08.1995; Association for Research in Vision and Ophtalmology
• Subjects: Adenosine - administration & dosage; Adenosine - pharmacology; Animals; Biological and medical sciences; Blood Flow Velocity - drug effects; Blood-Retinal Barrier - drug effects; Blood-Retinal Barrier - physiology; Cats; Choroid - blood supply; Choroid - drug effects; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Fundus Oculi; Hemodynamics - physiology; Infusions, Intravenous; Laser-Doppler Flowmetry; Optic Disk - blood supply; Optic Disk - drug effects; Retinal Vessels - drug effects; Retinal Vessels - physiology; Vertebrates: nervous system and sense organs; Human; Eye; Visual system; Regional blood flow; Adenosine; Purine nucleoside; Blood retinal barrier; Intravenous administration; Hemodynamics; Fundus of the eye
• ISSN: 0146-0404; 1552-5783

To determine the effect of intravascular adenosine on blood flow in the ocular fundus and to examine indirectly whether the blood-brain barrier to adenosine, which exists in the cerebrovasculature of the cat, is present in the eye of this animal. The noninvasive techniques of laser Doppler flowmetry and velocimetry along with fundus photography were used to measure the change in optic nerve head and choroidal and retinal blood flow during intravenous infusions of 0.18 and 0.6 mg/kg per minute of adenosine. Infusions of adenosine induced significant increases in choroidal blood flow (60% with 0.6 mg/kg per minute) but not in optic nerve head or retinal blood flows. The lack of effect of intravenously infused adenosine on the optic nerve and retinal circulations is most likely caused by the tight junctions in the vessels of these vascular beds, which prevent adenosine from reaching its receptors. Perivascular adenosine in the choroid most likely accounts for the increase in blood flow in this tissue.