These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Characterization of the endothelin binding site on bovine adrenomedullary chromaffin cells: comparison with vascular smooth muscle cells. Evidence for receptor heterogeneity.
    Author: Wilkes LC, Boarder MR.
    Journal: J Pharmacol Exp Ther; 1991 Feb; 256(2):628-33. PubMed ID: 1847205.
    Abstract:
    Specific binding sites for synthetic endothelin (ET) isoforms, ET-1 and ET-3 were studied in a bovine adrenomedullary chromaffin cell-rich preparation, and compared to those on A10 cells, a vascular smooth muscle cell line. Both [125I]ET-1 and [125I]ET-3 (2.5 x 10(-11) M) specifically bound to a single class of binding sites on the chromaffin cell preparation (apparent Kd 2.3 x 10(-10) and 1.4 x 10(-10) M, respectively), and the binding of both peptides was inhibited competitively by unlabeled ET-1, ET-3 and sarafotoxin S6b to an equal degree (IC50 values in the range 1.2 x 10(-10) to 3.1 x 10(-10) M). In contrast, only [125I]ET-1 (2.5 x 10(-11) M) specifically bound to A10 cells, to a single class of binding sites with apparent Kd of 1.5 x 10(-10) M. The same concentration of [125I]ET-3 displayed no evidence of specific binding. The binding of [125]ET-1 to A10 cells was inhibited competitively by unlabeled ET isoforms with the following order of potency: ET-1 (IC50, 3.1 x 10(-10) M) greater than Sarafotoxin S6b (IC50, 3.1 x 10(-9) M) greater than ET-3 (188 x 10(-9) M). ET-1 and ET-3 dose-dependently induced an increase in total inositol phosphate accumulation (the EC50 value of ET-1 was 1.3 x 10(-9) M). Neither ET-1 nor ET-3, up to 100 nM, affected the total inositol phosphate content of chromaffin cells.(ABSTRACT TRUNCATED AT 250 WORDS)
    [Abstract] [Full Text] [Related] [New Search]