摘要
利用离休孵育脑薄片和放射免疫测定其释放的精氨酸加压素（ＡＶＰ）方法，探讨糖皮质激素（ＧＣ）在不能进入细胞内的情况下，对去肾上腺大鼠的下丘脑薄片释放ＡＶＰ的快速影响及其可能的细胞膜机制。结果如下：（１）下丘脑薄片能够稳定地释放ＡＶＰ（２ｈ），其释放量为１５．４２±１．２８ｐｇ／ｍｉｎ；（２）牛血清白蛋白耦联皮质酮（Ｂ－ＢＳＡ）对ＡＶＰ的释放具有快速的（２０ｍｉｎ）抑制性效应，在１０￣（－７）─１０￣（－４）ｍｏｌ／Ｌ范围内呈剂量一效应关系；（３）ＧＣ细胞内受体拮抗剂ＲＵ４８６（１０￣（－４）─１０￣（－３）ｍｏｌ／Ｌ）能部分地阻断Ｂ─ＢＳＡ的快速抑制效应；（４）孵育液中Ｃａ￣（２＋）程度升高，Ｂ─ＢＳＡ的快速抑制效应明显增强；反之，孵育液中无Ｃａ￣（２＋）则Ｂ－ＢＳＡ的快速抑制效应有所减弱。表明ＧＣ在未进入细胞内的情况下也可快速地抑制大鼠下丘脑薄片释放ＡＶＰ，因此没有通过传统的基因组机制，而是由非基因组机制介导的，其作用部位在细胞膜水平上，可能是影响Ｃａ￣（２＋）的跨细胞膜内流通量或／和影响有Ｃａ￣（２＋）参与的ＡＶＰ释放过程的结果。
The hypothalamic slices of bilateral adrenalectomizcdrats werehcubated in microchambersand arginine vasopressin(AVP)released from the slices was measured by radioimmunoassay.Therapid effect of glucocorticoid(GC)without entering into cells on AVP release and its underlyingmechanism were investigated. The results were as follows:(1)AVP was rather steadily releasedfrom the slices at a rate of 15.42±1.28pg/min(2h);(2)Bovine serum albumin,conjugatedcorticosterone(B-BSA) rapidly inhibited AVP release(within 20min)in a dose-dependent man-ner at dosages from 10￣(-7) to￣(-4) mol/L.(3)The rapid inhibitory effect of B-BSA was partiallyblocked bv RU486 (10￣(-4)-10￣(-3)mol/L).(4)With the elevation of Ca￣(2+) level in the incubationmedia the rapid inhibitorv effect of B-BSA was enhanced,while the effect of B-BSA attenuatedin the absence of Ca￣(2+).These results suggested that GC might extracellularlv exert its rapid inhi-bition on A VP release from the hypothalamic slices of bilateral adrenalectomized rats,indi-cating that the classic genomic mechanism is not involved and this non-genomic effect might bemembrane-mediated,in which GC might change the Ca￣(2+) influx and/or the AVP releaseprocesses involving Ca￣(2+).
出处
《中国应用生理学杂志》
CAS
CSCD
1996年第2期111-114,共4页
Chinese Journal of Applied Physiology
基金
国家自然科学基金
