Distribution of γ-aminobutyric acid receptors in cultured adrenergic and noradrenergic bovine chromaffin cells
Distribution of γ-aminobutyric acid receptors in cultured adrenergic and noradrenergic bovine chromaffin cells
复制标题
DOI：
10.1002/jnr.10488
复制
发表时间：
2003-02-01
影响因子：
4.2
通讯作者：
Oset-Gasque, MJ
中科院分区：
文献类型：
--
作者：
Castro, E;González, MP;Oset-Gasque, MJ
用荧光成像技术记录单个嗜铬细胞胞浆[Ca~(2+)](I)，以表征和区分含有GABA(A)和GABA(B)受体亚型的细胞亚群。通过将这种方法与使用酪氨酸羟基酶(TH)、苯乙醇胺-N-甲基转移酶(PNMT)和谷氨酸脱羧酶(GAD)的特异性抗体与不同荧光探针连接的单个嗜铬细胞的免疫鉴定相结合，我们已经能够将单细胞钙反应归因于已鉴定的肾上腺素能和去甲肾上腺素能嗜铬细胞。GAD酶存在于30%的嗜铬细胞群中，主要位于肾上腺素能细胞中；86%的GAD(+)细胞也是PNMT+。GAD的表达与GABA受体的存在无关。GAD(+)组和GAD(-)组的GABA反应细胞频率相同。而GABA受体的表达与肾上腺素能表型相关。[Ca~(2+)](I)肾上腺素能细胞对GABA的反应比去甲肾上腺素能细胞更频繁。GABA(A)受体的分布更加均匀；大约90%的GABA反应细胞都有它们。GABA(B)受体的分布较为有限(存在于45%的反应细胞中)。GABA(A)和GABA(B)亚型的共同表达是规律；只有少数亚群(约12%)仅显示GABA(A)受体。当嗜铬细胞按GAD(+)/GAD(-)或PNMT+/PNMT(-)分类分离时，GABA受体亚型的分布方式相似，只是有微小的差异。这些数据表明，肾上腺髓质内固有的GABA能系统并不是一个旁分泌模型，在旁分泌模型中，一组细胞专门合成递质，另一组细胞作为特定的靶点。(C)2002年Wiley-Liss，Inc.
Fluorescence imaging techniques for recording cytosolic [Ca2+](i) from single chromaffin cells were used to characterize and discriminate between cell subpopulations containing gamma-aminobutyric acid (GABA)(A) and GABA(B) receptor subtypes. By combining this methodology with the immunoidentification of individual chromaffin cells using specific antibodies against tyrosine hydroxylase (TH), phenyl-etanolamine-N-methyl transferase (PNMT), and glutamic acid decarboxylase (GAD) linked to different fluorescent probes, we have been able to ascribe single-cell calcium responses to identified adrenergic and noradrenergic chromaffin cells. GAD enzyme is present in 30% of the chromaffin cell population, located primarily in adrenergic cells; 86% of GAD(+) cells were also PNMT+. GAD expression was not correlated with the presence of GABA receptors. GABA-responsive cells were found with equal frequency in the GAD(+) and GAD(-)groups. However, the expression of GABA receptor was correlated with the adrenergic phenotype. [Ca2+](i) responses to GABA were found more frequently in adrenergic than in noradrenergic cells. GABA(A) receptors are more evenly distributed; about 90% of GABA-responsive cells have them. GABA(B) receptors have a more restricted distribution (present in 45% of responding cells). The coexpression of both GABA(A) and GABA(B) subtypes is the rule; only a minor subpopulation (about 12%) displays exclusively GABA(A) receptors. GABA receptor subtypes are distributed in a similar way when chromaffin cells are separated according to GAD(+)/GAD(-) or PNMT+/PNMT(-)classifications, with only minor differences. These data indicate that the intrinsic GABAergic system in the adrenal medulla is not designed as a paracrine model in which a group of cells specializes in transmitter synthesis and a different group serves as a specific target. (C) 2002 Wiley-Liss, Inc.