1. Adenosine receptors in basolateral membranes of rat renal cortex.
- Author
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Jakubowski Z, Skowroński R, Matecki A, Mohuczy D, Pawełczyk T, Stepiński J, and Angielski S
- Subjects
- Adenosine analogs & derivatives, Adenosine metabolism, Adenosine Deaminase metabolism, Adenosine-5'-(N-ethylcarboxamide), Animals, Binding, Competitive, Chromatography, Thin Layer, In Vitro Techniques, Kinetics, Male, Membranes metabolism, Phenylisopropyladenosine metabolism, Rats, Rats, Wistar, Temperature, Kidney Cortex metabolism, Receptors, Purinergic metabolism
- Abstract
High affinity binding sites for adenosine were identified in rat kidney cortex basolateral membranes. Kinetic analysis indicates two sets of [3H]adenosine, [3H]ADO, binding sites, one with high affinity and Kd = 0.84 +/- 0.25 microM, one with low affinity and Kd = 4.74 +/- 0.37 microM. The ADO receptors were further characterized using ADO analogs as binding inhibitors. The most potent inhibitor of [3H]ADO binding was N-methyl-adenosine with a Kd of 5 microM, whereas 2-deoxyadenosine was about 50 times less potent. The binding of [3H]phenylisopropyladenosine, [3H]PIA, and [3H]-N-ethylcarboxamidoadenosine, [3H]NECA, to basolateral membranes was rapid and reversible. The Scatchard plot of [3H]PIA binding showed monophasic curves for experiments performed at 0 degrees C and 37 degrees C. The apparent Kd of [3H]PIA binding at 0 degrees C was 0.19 +/- 0.05 nM and 0.34 +/- 0.07 nM at 37 degrees C. The binding of [3H]NECA to basolateral membranes was found with an apparent affinity Kd of 110 +/- 50 nM at 0 degrees C. Pretreatment of membranes with N-ethylmaleimide (NEM) inhibited the [3H]PIA binding and did not affect the [3H]NECA binding. These results demonstrate that both A1 and A2 adenosine receptors are present in basolatertal membranes of rat kidney.
- Published
- 1992