Reactivity of Vascular Smooth Muscle in Hypertensive Rats
Reactivity of Vascular Smooth Muscle in Hypertensive Rats
复制标题
高血压大鼠血管平滑肌反应性
作者：
Edwin T Holloway;D. Bohr
研究了血压正常、自发性高血压、肾性高血压和醋酸脱氧皮质酮（DCA-）高血压大鼠股动脉螺旋条中血管平滑肌的反应性。三组高血压大鼠的 30 个试纸中，有 25 个出现自发节律性收缩，而血压正常大鼠的 10 个试纸中，只有 2 个出现自发节律性收缩。肾高血压和 DCA 高血压大鼠的试纸对肾上腺素和氯化钾 (KCl) 的阈值低于自发性高血压和正常血压大鼠的试纸。镧 (2.5 mM) 引起自发性高血压大鼠的所有 10 个试纸条收缩，但未能引起其他三组大鼠的任何试纸条收缩。锶 (5 mM) 引起自发性高血压大鼠 10 条试纸中的 8 条收缩，但其他三组 30 条试纸中仅 7 条引起收缩。高血压大鼠试纸对 KCl 刺激作出反应的张力发展的最佳钙浓度大约是正常血压大鼠试纸的两倍。 DCA 高血压大鼠的试纸对血管紧张素 II 的快速耐受性低于其他三组大鼠的试纸。这些结果量化了我们早期的观察结果，即高血压大鼠血管平滑肌的反应性与血压正常大鼠的血管平滑肌反应性存在显着差异。此外，该研究描绘了不同类型的实验性高血压中血管平滑肌反应的个体性。结果表明，高血压大鼠的血管平滑肌细胞膜比正常大鼠的血管平滑肌细胞膜更不稳定。
The reactivity of vascular smooth muscle in helical strips from femoral arteries of normotensive, spontaneously hypertensive, renal hypertensive, and deoxycorticosterone acetate— (DCA-) hypertensive rats was studied. Spontaneous rhythmic contractions occurred in 25 of the 30 strips from the three groups of hypertensive rats and in only 2 of the 10 strips from normotensive rats. Strips from renal and DCA hypertensive rats had lower thresholds to epinephrine and potassium chloride (KCl) than did strips from spontaneously hypertensive and normotensive rats. Lanthanum (2.5 mM) caused contraction of all 10 strips from spontaneously hypertensive rats but failed to cause contraction of any strip from the other three groups of rats. Strontium (5 mM) caused contraction in 8 of 10 strips from spontaneously hypertensive rats but caused contraction in only 7 of the 30 strips from the other three groups. The optimal calcium concentration for tension development in response to a KCl stimulus was approximately twice as high for strips from hypertensive rats as it was for strips from normotensive rats. Strips from DCA-hypertensive rats showed less tachyphylaxis to angiotensin II than did strips from the other three groups of rats. These results quantify our earlier observation that the reactivity of vascular smooth muscle from hypertensive rats is importantly different from that of normotensive rats. In addition, the study delineates individuality in vascular smooth muscle reactivity in different types of experimental hypertension. The results suggest that the cell membrane of the vascular smooth muscle in the hypertensive rat is more labile than that in the normal rat.