The tissue distribution of the human beta(3)-adrenoceptor studied using a monoclonal antibody: Direct evidence of the beta(3)-adrenoceptor in human adipose tissue, atrium and skeletal muscle

OBJECTIVE: To develop a monoclonal antibody that recognises an epitope of t he native beta(3)-adrenoceptor expressed on the extracellular surface of hu man cells and tissues. DESIGN: A high affinity monoclonal antibody, Mab72c, was raised against the human beta(3)-adrenoceptor expressed on a transfected mammalian cell line. RESULTS: In CHO (Chinese hamster ovary) cells transfected with beta(3)-adre noceptor cDNA, antibody labelling was found to be proportional to receptor density measured by the binding of the radiolabelled beta(3)-adrenoceptor a ntagonist, [I-125]iodocyanopindolol. The use of Mab 72c has demonstrated th e expression of the beta(3)-adrenoceptor in a variety of human tissues, inc luding gall bladder, prostate and colon, where a mRNA signal had been detec ted previously. This study also provides the first direct demonstration of the expression of beta(3)-adrenoceptors in human skeletal muscle, atrium an d adipose tissue. CONCLUSION: The development of this antibody represents an important additi on to the armentarium of reagents that are available to study the localisat ion of beta(3)-adrenoceptors in human tissues.