Endothelin-1 Significantly Increased Number of Specific High-Affinity 1,4-Dihydropyridine (DHP) Binding Sites Photolabelled on Vascular Smooth Muscle Cells with (-)-[3H]-Azidopine

Title:

Endothelin-1 Significantly Increased Number of Specific High-Affinity 1,4-Dihydropyridine (DHP) Binding Sites Photolabelled on Vascular Smooth Muscle Cells with (-)-[3H]-Azidopine

Creator:

Dřímal, J. and Koprda, V.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:9dad6e21-fe13-42dd-888d-2752a652b768
uuid:9dad6e21-fe13-42dd-888d-2752a652b768

Subject:

vascular smooth muscle, dihydropyridine receptor, photoaffinity labelling, (-)-[3H]-azidopine, ligand binding, endothelin-1, staurosporine, and S-( + )-niguldipine

Type:

article, model:article, and TEXT

Description:

The effects of endothelin-1 (ET-1) on surface membrane Ca2+ channels were studied on cultured human embryonal vascular smooth muscle cells (VSMC) and on isolated rat aorta using photoaffinity labelling with DHP Ca2+ channel antagonist (-)-[3H]-azidopine (AZI). The AZl-labelled saturable population of sites on VSMC with Bmax = 1.59±0.10 pmol/mg of protein and Kd = 5.40±1.70 nmol/1; and 1.32±0.11 pmol/mg w.w. and Kd = 1.09±0.20 nmol/1 in isolated rings of the rat aorta. Preincubation with ET-1 (0.1, 1.0 and 10 nmol/1) increased (in a concentration-dependent manner) the total number of sites specifically photolabelled on VSMC. The number of sites labelled with AZI on ET-1 preincubated VSMC increased markedly when divalent cations (Ca2+ or Mg2+ in other experiments) were present in the incubation medium. Specific photolabclling also significantly increased in VSMC pretreated with intrinsically photoreactive nifedipine. A protein kinase C inhibitor staurosporine, added to the incubation medium, significantly reduced the enhanced specific photolabelling after ET-1. The increase in specific photolabelling after ET-1 preincubation (+ 197±46 %; P<0.05) was also observed in rings of the rat aorta and it was significantly reduced after prcincubation with S-(+)-niguldipine.

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 1996 Volume:45 | Number:1

Harvested from:

CDK

Metadata only:

false