- Peptide CEMLRKKSGMQIALND, corresponding to amino acid residues 298-314 of rat ET-B (Accession P21451). 3rd intracellular loop.
- Rat and mouse brain lysates (1:500-1:2500).
- Western blot analysis of rat (lanes 1 and 3) and mouse (lanes 2 and 4) brain lysates:1,2. Guinea pig Anti-Endothelin Receptor B Antibody (#AGP-037), (1:500).
3,4. Guinea pig Anti-Endothelin Receptor B Antibody, preincubated with Endothelin Receptor B Blocking Peptide (#BLP-ER002).
- Following a broad screen of secondary antibodies, the following was used for this application:
#106-035-006 (Jackson ImmunoResearch).
Endothelins (ET-1, 2, and 3) are considered to be very powerful vasoconstrictive substances. In humans, endothelins mediate their actions via two specific G-Protein coupled receptors, ETAR and ETBR. Both ETAR and ETBR are present in the heart and in human myocardium at similar levels.1,2
The endothelin receptors differ in their ligand specificity. While ETAR has varying affinities for the endothelin isoforms (ET-1 > ET-2 > ET-3), ETBR shows no selective affinity.2,3
Subsequent studies have demonstrated the presence of endothelins in vascular, as well as in non-vascular, cells and tissues, having multiple biological activities.
Currently, there is increasing evidence that ET-1 may modulate mitogenesis, apoptosis, angiogenesis tumor invasion and the development of metastases.3
Until recently, it was thought that all cellular activities of the endothelins were mediated through their interactions with their cell surface receptors. However, a recent study demonstrated that cardiac nuclei also possess both ETAR and ETBR subtypes, which are functional and coupled to signaling mechanisms within the nuclear membrane.2
Hypermethylation of the ETBR correlated with transcriptional down-regulation and reduced expression of ETB receptor was observed in several prostate, bladder and colon cancer cell lines.3