AN INCREASED CALCIUM SENSITIVITY OF MESENTERIC RESISTANCE VESSELS IN YOUNG AND ADULT SPONTANEOUSLY HYPERTENSIVE RATS
AN INCREASED CALCIUM SENSITIVITY OF MESENTERIC RESISTANCE VESSELS IN YOUNG AND ADULT SPONTANEOUSLY HYPERTENSIVE RATS
复制标题
DOI：
10.1111/j.1476-5381.1980.tb10977.x
复制
发表时间：
1980-01-01
影响因子：
7.3
通讯作者：
NYBORG, N
中科院分区：
文献类型：
--
作者：
MULVANY, MJ;NYBORG, N
1我们测量了自发性高血压（SHR）和对照Wistar京都（WKY）大鼠100 - 200 μ m肠系膜阻力血管的离体节段对去甲肾上腺素刺激和钾去极化的钙敏感性。这些大鼠要么是年轻的（4周），要么是成年的（4个月），即在SHR血压升高之前或之后的年龄。实验是在血管壁神经末梢摄取去甲肾上腺素和钾诱导的去甲肾上腺素释放的影响被消除的条件下进行的。2在只有细胞外钙似乎被去除的条件下，SHR和WKY血管对去甲肾上腺素的反应相似。当随后用去甲肾上腺素最大刺激时，SHR血管的钙敏感性（Ca-ED 50 ≤ 0.1 mm）大于WKY血管的钙敏感性（Ca-ED 50 ≤ 0.2 mm）。当通过钾去极化时，所有血管对钙的敏感性降低，并且两个年龄组中SHR和WKY血管的钙敏感性几乎没有差异（Ca-ED 50 ≤ 0.8 mm）。3结果表明，尽管SHR平滑肌细胞膜的钾（电位）依赖性钙渗透性正常，但去甲肾上腺素诱导的钙渗透性异常高。这种异常的存在下，从年轻的SHR的血管表明，它可能是一个因素参与的高血压的病因。
1We have measured the calcium sensitivity in response to noradrenaline stimulation and potassium depolarization of isolated segments of 100 to 200 μmmesenteric resistance vessels from spontaneously hypertensive (SHR) and control Wistar‐Kyoto (WKY) rats. The rats were either young (4 wk) or adult (4 months), that is of ages before or after the SHRs had developed elevated blood pressure. Experiments were performed under conditions in which the effect of noradrenaline uptake by, and the potassium‐induced noradrenaline release from, the nerve terminals in the vessel walls was eliminated.2The response of the SHR and WKY vessels to noradrenaline under conditions where only the extracellular calcium appeared to have been removed was similar. When subsequently stimulated maximally by noradrenaline, the calcium‐sensitivity of the SHR vessels (Ca‐ED50≃ 0.1 mm) was greater than that of the WKY vessels (Ca‐ED50≃ 0.2 mm). When depolarized by potassium, all vessels were less sensitive to calcium and there was little difference in the calcium sensitivity of SHR and WKY vessels in either age group (Ca‐ED50≃ 0.8 mm).3The results suggest that whereas the potassium (potential)‐dependent calcium permeability of the SHR smooth muscle cell membrane is normal, the noradrenaline‐induced calcium permeability is abnormally high. The presence of this abnormality in the vessels from the young SHRs suggests that it may be a factor involved in the aetiology of hypertension in the SHR.