豚鼠和大鼠脑不同区域中内皮素-1和内皮素-3刺激磷酸肌醇分解的特征存在差异。
Characteristics of endothelin-1 and endothelin-3 stimulation of phosphoinositide breakdown differ between regions of guinea-pig and rat brain.
作者信息
Crawford M L, Hiley C R, Young J M
机构信息
Department of Pharmacology, University of Cambridge, UK.
出版信息
Naunyn Schmiedebergs Arch Pharmacol. 1990 Mar;341(3):268-71. doi: 10.1007/BF00169742.
Endothelin-3 was almost equipotent with endothelin-1 (ET-1) in stimulating phosphoinositide hydrolysis, as indicated by [3H]inositol phosphate formation, in cross-chopped slices of guinea-pig cerebellum, rat cerebellum and rat cerebral cortex. The magnitude of [3H]inositol phosphate formation was greatest in guinea-pig cerebellum, approximately 10-fold over basal levels. The similar level of [3H]IP1 accumulation produced by 1 mumol.l-1 ET-1 in rat cerebellum and cerebral cortex (circa 3-fold over basal) did not mirror the large difference in high-affinity [125I]ET-1 binding sites in the two regions. Moreover, the EC50 for ET-induced [3H]IP1 formation differed markedly between the three tissues (7 +/- 2 nmol.l-1 in rat cerebral cortex, 65 +/- 15 nmol.l-1 in guinea-pig cerebellum and greater than 200 nmol.l-1 in rat cerebellum). Only in rat cerebral cortex was the EC50 of the same order as has been reported for peripheral responses to ET-1.
在豚鼠小脑、大鼠小脑和大鼠大脑皮质的交叉切片中，内皮素 -3 在刺激磷酸肌醇水解方面与内皮素 -1（ET-1）几乎具有同等效力，这可通过 [3H] 肌醇磷酸的形成来表明。[3H] 肌醇磷酸的形成量在豚鼠小脑中最大，比基础水平高约 10 倍。1 μmol·l-1 的 ET-1 在大鼠小脑和大脑皮质中产生的 [3H]IP1 积累水平相似（比基础水平高约 3 倍），但这并未反映出这两个区域高亲和力 [125I]ET-1 结合位点的巨大差异。此外，ET 诱导的 [3H]IP1 形成的 EC50 在这三种组织之间明显不同（大鼠大脑皮质中为 7±2 nmol·l-1，豚鼠小脑中为 65±15 nmol·l-1，大鼠小脑中大于 200 nmol·l-1）。只有在大鼠大脑皮质中，EC50 与报道的外周对 ET-1 的反应处于同一数量级。
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