摘要
本实验利用高体孵育脑薄片和放射免疫测定精氨酸加压素（ＡＶＰ）的方法，初步探讨了牛血清白蛋白耦联皮质酮（Ｂ－ＢＳＡ，不易进入细胞内）对大鼠下丘脑薄片（含室旁核和视上核）释放ＡＶＰ的影响和可能机制。结果：（１）Ｂ－ＢＳＡ（１０－７─１０－４ｍｏｌ／Ｌ）在２０ｍｉｎ内对大鼠下丘脑薄片ＡＶＰ的释放具有明显的抑制性效应，且呈剂量一效应关系；（２）ＲＵ４８６（１０－４─１０－３ｍｏｌ／Ｌ）能部分地阻断Ｂ－ＢＳＡ的抑制效应；（３）Ｂ－ＢＳＡ的抑制效应随孵育液中Ｃａ２＋浓度的升高而明显增强；（４）在有新毒素（１０－３─１０－２ｍｏｌ／Ｌ）存在的情况下，Ｂ－ＢＳＡ的抑制效应显著增强。上述结果表明糖皮质激素在未进入细胞内的情况下亦可抑制大鼠下丘脑薄片释放ＡＶＰ。此作用发生在细胞膜水平上，由非基因组机制所介导，可能是影响Ｃａ２＋跨细胞膜流动的结果。
The arginine vasopressin (AVP) released from rat hypothalamic slices containing paraventricular and supraoptic nuclei sectioned with vibratome and incubated in microchambers was measured by radioimmunoassay. The effect of bovine serum albuminconjugated corticosterone (B-BSA) on the AVP release was investigated. The results were as follows: (1)B-BSA, within 20 min, inhibited the AVP release in a dose-dependent manner from 10-7 to 10-4 mol/L. (2)The inhibitory effect of B-BSA was partially blocked by RU486 (10-4-10-3 mol/L). (3)With the elevation of Ca2+ in the incubation medium the inhibitory effect of B-BSA was enhanced. (4) The inhibitroy effect of B-BSA was also enhanced in the presence of neomycin (10-3-10-2mol/L). These results suggested that glucocorticoid, without entering into cells, could inhibit AVP release from rat hypothalamic slices. This effect might be mediated via a non-genomic mechanism involving a change of Ca2+ influx across the cell membrane.
出处
《生理学报》
CAS
CSCD
北大核心
1996年第2期173-178,共6页
Acta Physiologica Sinica
基金
国家自然科学基金
关键词
下丘脑
精氨酸加压素
牛血清白蛋白
耦联皮质酮
hypothalamic slice
arginine vasopressin
bovine serum albumin-conjugated corticosterone
RU486
calcium
