Visualization of adenosine A1 receptors in the human and the guinea-pig kidney.

Adenosine A1 receptors were localized in sections of human and guinea-pig kidney with quantitative receptor autoradiography and [3H]cyclohexyladenosine [( 3H]CHA) used as ligand. The binding sites had the characteristics of an A1 receptor. In the human kidney a high density of receptor sites was measured over the glomeruli. In the guinea-pig kidney the receptor sites were localized in the inner and outer medulla although a low density of binding was also seen over the glomeruli. The functional significance of the findings is discussed.