Portellos M, Riva C E, Cranstoun S D, Petrig B L, Brucker A J
Scheie Eye Institute, University of Pennsylvania, Philadelphia 19104, USA.
Invest Ophthalmol Vis Sci. 1995 Aug;36(9):1904-9.
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.
确定血管内注射腺苷对眼底血流的影响，并间接检测猫脑血管系统中存在的血脑屏障对腺苷的屏障作用在该动物的眼中是否存在。
采用激光多普勒血流仪和测速仪的非侵入性技术以及眼底摄影，测量静脉输注每分钟0.18和0.6毫克/千克腺苷期间视神经乳头、脉络膜和视网膜血流的变化。
输注腺苷可使脉络膜血流显著增加（每分钟0.6毫克/千克时增加60%），但对视神经乳头或视网膜血流无影响。
静脉注射腺苷对视神经和视网膜循环无影响，很可能是由于这些血管床的血管紧密连接，阻止了腺苷到达其受体。脉络膜血管周围的腺苷很可能是该组织血流增加的原因。
