The Japanese Journal of Pharmacology | |
The Non-neuronal Cholinergic System | |
Heinz Kilbinger1  Jörg Kriegsmann2  Ignaz Wessler1  C. James Kirkpatrick2  Ron E. Unger2  Fernando Bittinger2  | |
[1] Institute of Pharmacology, Johannes Gutenberg University;Institute of Pathology | |
关键词: Non-neuronal cholinergic system; Endothelium; Signal transduction; | |
DOI : 10.1254/jjp.85.24 | |
学科分类:药理学 | |
来源: Nihon Yakuri Gakkai Henshuubu / Japanese Pharmacological Society | |
【 摘 要 】
References(25)Cited-By(38)An increasing body of knowledge indicates that the cholinergic system is not confined to the nervous system, but is practically ubiquitous. The present paper will address the question of the non-neuronal cholinergic system in vascular endothelial cells (EC). In tissue sections of human skin, immunohistochemical studies using confocal laser scanning microscopy showed ChAT (choline acetyltransferase) activity in the EC of dermal blood vessels. Positive ChAT immunoreactivity was also demonstrated in monolayer cultures of human umbilical vein EC (HUVEC) and a human angiosarcoma EC line (HAEND). That the synthesizing enzyme is not only present in EC, but also active was shown by measuring ChAT activity. Thus, in HUVEC cultures, ChAT activity amounted to 0.78 ± 0.15 nmol · mg protein−1 · h− 1 (n = 3), but was only partially (about 50%) inhibited by the ChAT inhibitor bromoacetylcholine (30 μM). In HPLC measurements, a concentration of 22 ± 2 pmol acetylcholine (ACh) per 106 cells was found (n = 6). However, using a cholinesterase-packed analytical column to check the identity of the acetylcholine peak, the peak height was found to be reduced, although a significant peak still remained, indicating the existence of a compound closely related to ACh. Further immunocytochemical experiments indicated that EC in vitro also express the vesicular acetylcholine transporter (VAChT) system. Preliminary immunoelectron microscopic studies suggest a topographical association of VAChT with endothelial endocytotic vesicles. The presented experiments clearly demonstrate the existence of essential elements of the cholinergic system (ChAT, VAChT, ACh) in the human endothelium. The biological functions of ACh synthesized by endothelial cells are the focus of ongoing research activity.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
RO201912080714791ZK.pdf | 322KB | download |