However, these experiments do not permit the undeniable proof of D2R-A2AR oligomerizathus; thus, we developed a TR-FRET-based strategy, because only this kind of tool permits the demonstration of direct receptor-receptor interactions at the cell surface when expressed at a physiological level (Albizu et al., 2010; Kern et al., 2012; Maurel et al., 2008).
An immunohistochemical method (avidin biotin peroxidase complex; ABC-HRP) was performed on paraffin embedded sections from breast cancer patients for demonstration of estrogen receptor (ER), progesterone receptor (PR), p53, c-erbB-2, and Ki-67 protein expression.
The similar brightness values obtained for Y1sfGFP and GAPsfGFP particles were initially surprising, given previous demonstration of Y1 receptor dimers by FRET [38] and similar analysis for μ-opioid receptor-GFP suggesting 1.5 hold higher brightness than free cytoplasmic GFP [20].
Indeed, a number of studies have demonstrated that specific V1R- and V2R-expressing vomeronasal neurons respond to known pheromones [ 22- 24]; however, formal proof that the V1R and V2R are pheromone receptors awaits a direct demonstration of ligand-receptor interactions between such compounds and these receptors.
The demonstration of somatostatin receptor status by In-octreotide or Ga-labelled peptide PET/CT imaging positively predicts response to somatostatin analogue therapy.
Peptide receptor scintigraphy in humans started with the demonstration of somatostatin receptor-positive tumours in patients using a radioiodinated somatostatin analogue [ 2].
With the demonstration of EPO receptors in astrocytes, neurons, and brain capillary endothelial cells as well as the ability of EPO to cross the blood-brain barrier, a potential for EPO-mediated central nervous system radioprotection is postulated.
Since the first demonstration of GLP-1 receptor cloning and functional expression 20 years ago, enormous research efforts have been focused on developing GLP-1 receptor agonists to treat diabetes, resulting in first-in-human proof-of-concept studies in the early 2000s.
Demonstration of vitamin D receptor, 1α-hydroxylase, and vitamin D-binding protein in the hypothalamus further supports a role of vitamin D deficiency in the generation of head pain.
Since the first demonstration of the P2X3 receptor in the human urothelium [ 31], only few studies confirmed the presence of P2X3 protein [ 32], while expression analyses revealed no P2X3 mRNA in the human urothelium [ 33].
