(-)-[3H]Dihydroalprenolol binding in subcellular fractions of rat cortex following noradrenergic denervation.

Two weeks after noradrenergic denervation, beta-adrenergic receptor binding increased in 2 of 3 crude fractions of rat cortical homogenates, while the relative distribution of binding was unchanged on continuous sucrose density gradients of the crude synaptosomal fraction. When rat glioma cells were fractionated by the same methods, a band of membranes with beta-adrenergic receptor binding sedimented at the same sucrose density as synaptosomes. Thus membrane receptors remained associated with synaptosomes even in the absence of noradrenergic nerve terminals suggesting that a portion of these receptors are either glial or associated with non-noradrenergic nerve terminals.