alpha 2-Adrenergic receptors are associated with renal proximal tubules

The location of alpha 2-adrenergic receptors has been investigated in the guinea pig kidney. We used an in vitro labeling autoradiographic technique to examine the distribution of specific [3H]clonidine binding sites with the light microscope. alpha 2-Adrenergic receptors appeared to be located predominantly on the proximal tubules. The implication of this finding for renal physiology is discussed.