Although experimental evidence indicates a probable role of epidermal growth factor receptor (EGFr) in clinical oncology, no standardized method for its determination has been yet described, and discrepant results have been reported in clinical studies. In standardizing a radioligand binding assay for EGFr, we evaluated the causes of variability in each step of the assay. Entrapment of EGFr in ...

Determination of estrogen receptor content in 82 breast cancer specimens with immunocytochemical estrogen receptor assay (ER-EIA) (Abbott) was compared with our routinely used binding assay using 125I-estradiol as radioligand with Scatchard plot analysis of the binding data. Although the estrogen receptor content measured with the ER-EIA was approximately 2-fold higher compared with the binding...

Binding of the tricyclic antidepressant imipramine (IMI) to neutral and negatively charged lipid membranes was investigated using a radioligand binding assay combined with centrifugation or filtration. Lipid bilayers were composed of brain phosphatidylcholine (PC) and phosphatidylserine (PS). IMI binding isotherms were measured up to IMI concentration of 0.5 mmol/l. Due to electrostatic attract...

An agonist is a signalling molecule which binds to a receptor inducing a confor mational change which produces a response An antagonist is a drug which attenuates the e ect of an agonist Antagonists may be competitive non competitive or uncompetitive A competitive antagonist binds to a region of the receptor which overlaps the region bound by an agonist The agonist and antagonist compete for th...

The binding affinities of racemic derivatives of propranolol to ƒÀ-adrenoceptors were examined by means of radioligand binding assay to determine whether racemic propranolol shows biphasic binding to ,ƒÀ-adrenoceptors in a displacement experiment. Rat brain was used and the ƒÀadrenoceptor binding assay was carried out with 3H-dihydroalprenolol as the radioligand. A higher affinity of l-proprano...

The luteinizing hormone (LH) receptor plays a pivotal role in reproduction. The high-molecular-weight (HMW) human chorionic gonadotropin (hCG) and LH are the endogenous ligands of this receptor and bind to its large N terminus. The present study characterizes the binding of a new low-molecular-weight (LMW) radioligand, [H]5-amino-2-methylsulfanyl-4-[3-(2-morpholin-4-ylacetylamino)-phenyl]-thien...

The calcitonin receptor-like receptor (CRLR) can function as either a receptor for calcitonin gene-related peptide (CGRP) or for adrenomedullin (ADM), depending upon the coexpression of a novel family of single transmembrane proteins, which we have called receptor activity modifying proteins or RAMPs. RAMPs 1, 2, and 3 transport CRLR to the plasma membrane with similar efficiencies, however RAM...