Evidence for A_{1} and A_{\rm 2B} adenosine receptors in baby hamster kidney (BHK) cells

Article type: Research Article

Authors: Mittal, Rashmi A. | Tan, Chee‐Hong^; | Khoo, Hoon‐Eng

Affiliations: Department of Biochemistry, Faculty of Medicine, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260

Note: [] Corresponding author: Tel.: +65 8743245; Fax: +65 7791453; E‐mail: bchtanch@ nus.edu.sg.

Abstract: Adenosine is known to produce biphasic effects in the renal tissues via adenosine receptors. However, the presence of more than one subtype of adenosine receptor on a type of kidney cell or tissue has not been conclusively demonstrated. To address this issue, we investigated the presence of A_{1} and A_{2} adenosine receptors in baby hamster kidney (BHK) cells by use of radioligand binding and the reverse transcription‐polymerase chain reaction. Ligand binding studies with (^{3}H)‐DPCPX revealed a single class of binding site with a K_\mathrm{D} of 9.2 \pm 2.0 nM, a B_{\max} of 1.7 \pm 0.2 pmol/mg protein and a pharmacological profile characteristic of A_{1} adenosine receptor on the BHK cell membrane. As the presence of A_{2} adenosine receptors could not be conclusively determined by ligand binding studies, the more sensitive method of RT‐PCR was employed. The presence of A_{1} and A_\mathrm{2B} adenosine receptors was detected by RT‐PCR with specific primers and the subsequent sequencing of the resultant amplification product. The sequences obtained were 75–90% homologous to the respective adenosine receptor mRNA of rat, mouse and human.

Keywords: Baby hamster, kidney, adenosine receptors, characterization, RT‐PCR

Journal: Biofactors, vol. 10, no. 1, pp. 25-33, 1999