In:
Hypertension, Ovid Technologies (Wolters Kluwer Health), Vol. 30, No. 4 ( 1997-10), p. 837-844
Abstract:
Abstract Endothelin-1 (ET-1) is formed from its precursor preproET-1 via the cleavage of the intermediate bigET-1 by endothelin-converting enzyme (ECE-1). However, the subcellular site at which this step occurs is not clear: It could occur intravesicularly along the secretory pathway or bigET-1 might be released and processed extracellularly. To address this point, we have developed an integrated autocrine system that uses a recombinant Chinese hamster ovary (CHO) luciferase reporter cell line that permanently expresses the human ET A receptor. Into these cells we transiently transfected human ECE-1a cDNA, either together with the human preproET-1 cDNA (as an endogenous source of bigET-1), or alone (in which case exogenous bigET-1 was added). Phosphoramidon inhibited the conversion of exogenous bigET-1 (IC 50 =5 to 30 μmol/L) much better than that of endogenous bigET-1 (IC 50 〉 1 mmol/L). Both conversions showed similar high yields (20% to 100%) that depended on the amount of ECE-1a expressed. Thus, ECE-1a has two equally relevant activities in this recombinant system for CHO cells: (1) an intracellular, probably intravesicular activity, corresponding to the ECE-1a–mediated step of ET-1 biosynthesis and (2) an extracellular activity at the plasma membrane. If this is also the case for endothelial cells, ECE-1a inhibitors would have to cross the plasma and vesicle membranes to be effective. The present system could be useful for screening such inhibitors.
Type of Medium:
Online Resource
ISSN:
0194-911X
,
1524-4563
DOI:
10.1161/01.HYP.30.4.837
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
1997
detail.hit.zdb_id:
2094210-2
