Sjögren A, Edvinsson L
Department of Internal Medicine, University Hospital of Lund, Sweden.
Acta Physiol Scand. 1988 Nov;134(3):429-36. doi: 10.1111/j.1748-1716.1988.tb08511.x.
Contractile responses to prostaglandin F2 alpha, serotonin, noradrenaline, and potassium were examined in isolated intramyocardial arteries of Wistar rats 8 weeks after the induction of diabetes mellitus by administration of streptozotocin (STZ). The concentration-response curves obtained were compared with those noted in vessels both from age- and from weight-matched control rats. Light and electron microscopy did not reveal any major change in coronary artery wall thickness or morphology. There was no difference in the pattern of vasomotor responses between the two control groups. Contractile responses to prostaglandin F2 alpha, and potassium were significantly reduced, while contractile responses to serotonin and noradrenaline were unaltered in coronary arteries from diabetic rats. The vasomotor responses to noradrenaline and potassium showed a biphasic pattern in control vessels, i.e. contraction noted at high agonist concentrations was preceded by slight, but reproducible relaxation at lower concentrations. In diabetic vessels these relaxant responses were absent. The contraction produced by noradrenaline was markedly enhanced by the presence of propranolol in both diabetic and control vessels. Dilator responses to verapamil, diltiazem, nifedipine, papaverine and magnesium were studied in serotonin-precontracted coronary arteries; the concentration-response curves obtained by verapamil and diltiazem were shifted to the right in diabetic vessels. It appears justified to use vessels from age-matched rats as controls when vasomotor reactivity in coronary arteries from STZ-diabetic rats is investigated. The reduction in contractile responses to prostaglandin F2 alpha and potassium, and the reduction or lack of relaxant responses to noradrenaline, potassium, verapamil and diltiazem, in diabetic coronary arteries, indicate a selective modification of the coronary circulation by the diabetic disease.
通过注射链脲佐菌素（STZ）诱导糖尿病8周后，检测了Wistar大鼠离体心肌内动脉对前列腺素F2α、5-羟色胺、去甲肾上腺素和钾的收缩反应。将得到的浓度-反应曲线与年龄和体重匹配的对照大鼠血管中的曲线进行比较。光镜和电镜检查未发现冠状动脉壁厚度或形态有任何重大变化。两个对照组的血管舒缩反应模式没有差异。糖尿病大鼠冠状动脉对前列腺素F2α和钾的收缩反应显著降低，而对5-羟色胺和去甲肾上腺素的收缩反应未改变。对照血管中对去甲肾上腺素和钾的血管舒缩反应呈双相模式，即在高激动剂浓度下出现收缩之前，低浓度时会有轻微但可重复的舒张。糖尿病血管中没有这些舒张反应。在糖尿病和对照血管中，普萘洛尔的存在均显著增强了去甲肾上腺素产生的收缩作用。在5-羟色胺预收缩的冠状动脉中研究了对维拉帕米、地尔硫䓬、硝苯地平、罂粟碱和镁的舒张反应；糖尿病血管中维拉帕米和地尔硫䓬得到的浓度-反应曲线向右移动。在研究STZ诱导糖尿病大鼠冠状动脉的血管舒缩反应性时，使用年龄匹配大鼠的血管作为对照似乎是合理的。糖尿病冠状动脉中对前列腺素F2α和钾的收缩反应降低，以及对去甲肾上腺素、钾、维拉帕米和地尔硫䓬的舒张反应降低或缺乏，表明糖尿病对冠状动脉循环有选择性改变。
