Dóra E
Acta Physiol Hung. 1986;68(2):183-97.
The purpose of the present study was to elucidate the importance of extracellular adenosine (ADO) in the regulation of cerebrocortical microcirculation during rest, hypoxia, and brain activation. Cerebrocortical microcirculation and fluorescence of reduced nicotinamide adenine dinucleotide (NADH) were measured by surface fluororeflectometry through a cranial window. Arterial hypoxia and brain activation were produced by respirating the animals with a gas mixture containing 6-7% O2 and by injecting 4-6 mg/kg metrazol into the lingual artery, respectively. These reactions were used as test before and after theophylline (THEO) treatment. In some of the experiments only the cortical area beneath the cranial window was treated with THEO (10(-4) M), in others 2 X 10(-4) mol/kg THEO was injected intraperitoneally. Potency of THEO in antagonizing the cerebral blood flow (CBF) increasing effect of topically applied ADO was also tested. It was found that superfusion of the brain cortex with artificial cerebrospinal fluid (mock CSF) containing 10(-4) M THEO does not alter resting CBF, but inhibits the CBF increasing effect of 10(-6) M and 10(-5) M ADO by approximately 70% and 40%, respectively. Intraperitoneally injected THEO increased CBF by approximately 60%, which has been attributed mostly to its action on the systemic circulation. Under control conditions, arterial hypoxia and epileptic seizures increased CBF by approximately 150% and 300%, respectively. Since neither topical nor systemic THEO treatment altered the vasodilatory and CBF increasing potency of arterial hypoxia and attenuated these effects of epilepsy slightly, it was concluded that extracellular ADO is not a critical factor in the regulation of cerebrocortical microcirculation.
本研究的目的是阐明细胞外腺苷（ADO）在静息、缺氧及脑激活状态下对脑皮质微循环调节中的重要性。通过颅骨视窗，采用表面荧光反射法测量脑皮质微循环及还原型烟酰胺腺嘌呤二核苷酸（NADH）的荧光强度。分别通过用含6 - 7%氧气的混合气体呼吸动物以及向舌动脉注射4 - 6mg/kg戊四氮来制造动脉缺氧和脑激活状态。这些反应在茶碱（THEO）治疗前后用作测试。在一些实验中，仅在颅骨视窗下方的皮质区域用THEO（10⁻⁴M）处理，在其他实验中，腹腔注射2×10⁻⁴mol/kg THEO。还测试了THEO拮抗局部应用ADO增加脑血流量（CBF）作用的效能。结果发现，用含10⁻⁴M THEO的人工脑脊液（模拟脑脊液）灌注大脑皮质不会改变静息状态下的CBF，但分别抑制10⁻⁶M和10⁻⁵M ADO增加CBF的作用约70%和40%。腹腔注射THEO使CBF增加约60%，这主要归因于其对体循环的作用。在对照条件下，动脉缺氧和癫痫发作分别使CBF增加约150%和300%。由于局部或全身应用THEO治疗均未改变动脉缺氧的血管舒张和增加CBF的效能，且仅轻微减弱癫痫的这些作用，因此得出结论：细胞外ADO不是调节脑皮质微循环的关键因素。
