Metzger H P, Savas Y
Dept. of Physiology, Medizinische Hochschule Hannover, Fed. Rep. of Germany.
Adv Exp Med Biol. 1988;222:411-8. doi: 10.1007/978-1-4615-9510-6_49.
The beneficial influence of calcium antagonists in restoring the disturbed circulation and metabolism towards its normal level has been described for a variety of circulatory disorders (arteriosclerosis, ischemia, hypertension). To date, however, little information exists concerning the physiological effects of the blocking molecules on cerebral blood flow (CBF) and oxygen tension at the organ surface (sPO2). White rats (Wistar-Frömter strain, N = 56, 180-250 g bw) were anesthetized with ketamine-xylazin, and artificially ventilated until normal acid-base status was achieved. Polarographic multi-wire O2 and H2 electrodes (15 microns diameter, 1 g weight) were balanced on the open brain through a cranial window drilled into the skull-cap in order to perform surface PO2 and hydrogen clearance measurements. Two different calcium antagonists, verapamil and flunarizine, were tested in order to verify structural differences of the molecules. Infusion of verapamil (7.5 micrograms/kg.min) and flunarizine (0.3 mg/kg.min) induced an increase in CBF by 55%/h (verap.) and by 62%/h (flun.) respectively while the controls (infusion of equal amounts of ringer-lactate) remained constant, ranging between 0.5 and 2.7 ml/g.min (n = 25 measurements). Surface PO2 improved distinctly in response to verapamil (39% increase) but was uneffected by flunarizine (less than 1%). Both drugs, however, lowered MAP by 18% (verap.) and by 33% (flun.) respectively probably due to peripheral vasodilatation and to the lowering of heart minute volume. In comparison with flunarizine the small MAP change after verapamil has resulted in the rise in CBF and sPO2.(ABSTRACT TRUNCATED AT 250 WORDS)
钙拮抗剂在使紊乱的循环和代谢恢复至正常水平方面的有益影响，已在多种循环系统疾病（动脉硬化、缺血、高血压）中得到描述。然而，迄今为止，关于这些阻断分子对脑血流量（CBF）和器官表面氧张力（sPO2）的生理作用，所知甚少。用氯胺酮 - 赛拉嗪麻醉Wistar - Frömter品系的白色大鼠（N = 56，体重180 - 250克），并进行人工通气，直至达到正常酸碱状态。通过在颅骨上钻的颅窗，将极谱多线氧和氢电极（直径15微米，重量1克）置于暴露的脑表面，以进行表面PO2和氢清除率测量。为了验证分子的结构差异，测试了两种不同的钙拮抗剂，维拉帕米和氟桂利嗪。输注维拉帕米（7.5微克/千克·分钟）和氟桂利嗪（0.3毫克/千克·分钟）分别使CBF每小时增加55%（维拉帕米）和62%（氟桂利嗪），而对照组（输注等量的乳酸林格液）保持恒定，在0.5至2.7毫升/克·分钟之间（n = 25次测量）。表面PO2对维拉帕米有明显改善（增加39%），但不受氟桂利嗪影响（增加不到1%）。然而，两种药物均分别使平均动脉压（MAP）降低18%（维拉帕米）和33%（氟桂利嗪），这可能是由于外周血管扩张和心输出量降低所致。与氟桂利嗪相比，维拉帕米后MAP的小变化导致了CBF和sPO2的升高。（摘要截短于250字）
