Gong D, Urono T, Nagakura Y, Matsuoka Y, Kubota K
Department of Neurology, Shanghai Medical University, People's Republic of China.
Brain Res. 1989 Mar 13;482(1):122-8. doi: 10.1016/0006-8993(89)90548-9.
Effects of perfusion flow rate and three vasoconstrictors, phenylephrine, prostaglandin F2 alpha (PGF2 alpha) and serotonin, on isolated, perfused brain preparations of spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto rats (WKY) were investigated. The basal perfusion pressure of the cerebral vascular beds at a flow rate of 2.5 ml/min was 48 +/- 3 mm Hg (n = 11) in SHR and 32 +/- 2 mm Hg (n = 12) in WKY (P less than 0.005). The perfusion pressures at all flow rates tested (2.5-6.5 ml/min) in SHR were significantly greater than those in WKY. Concentration-perfusion pressure curves for the vasoconstrictors showed that the brain vascular bed was much more reactive to serotonin compared with phenylephrine and PGF2 alpha. EC50 values (-logM) for serotonin in the perfused brains of SHR and WKY were 7.0 +/- 0.06 (n = 10) and 6.5 +/- 0.06 (n = 11), respectively (P less than 0.01). There were no differences in EC50 values for phenylephrine or PGF2 alpha between SHR and WKY. Exogenous serotonin and phenylephrine caused significantly greater maximal vasoconstrictor responses in SHR compared with WKY, while the pressor response to PGF2 alpha was very weak and no significant difference between SHR and WKY preparations was observed. These results indicate that cerebral vascular beds in SHR exhibit higher cerebrovascular resistance than those in WKY. and that reactivity and sensitivity to serotonin and reactivity to phenylephrine in SHR rats are enhanced to a greater extent compared to WKY.
研究了灌注流速以及三种血管收缩剂（去氧肾上腺素、前列腺素F2α（PGF2α）和5-羟色胺）对自发性高血压大鼠（SHR）和血压正常的Wistar-Kyoto大鼠（WKY）的离体灌注脑标本的影响。在流速为2.5 ml/min时，SHR脑血管床的基础灌注压为48±3 mmHg（n = 11），WKY为32±2 mmHg（n = 12）（P<0.005）。在所有测试流速（2.5 - 6.5 ml/min）下，SHR的灌注压均显著高于WKY。血管收缩剂的浓度-灌注压曲线表明，与去氧肾上腺素和PGF2α相比，脑血管床对5-羟色胺的反应性更强。SHR和WKY灌注脑中5-羟色胺的半数有效浓度值（-logM）分别为7.0±0.06（n = 10）和6.5±0.06（n = 11）（P<0.01）。SHR和WKY之间去氧肾上腺素或PGF2α的半数有效浓度值没有差异。与WKY相比，外源性5-羟色胺和去氧肾上腺素在SHR中引起的最大血管收缩反应显著更大，而对PGF2α的升压反应非常弱，在SHR和WKY标本之间未观察到显著差异。这些结果表明，SHR的脑血管床比WKY的表现出更高的脑血管阻力，并且与WKY相比，SHR大鼠对5-羟色胺的反应性和敏感性以及对去氧肾上腺素的反应性增强程度更大。
