[3H]Spiroperidol binding in normal and denervated carotid bodies

Specific dopamine receptors were studied in freshly dissected, unhomogenized rabbit carotid bodies incubated in [3H]spiroperidol. Total binding and non-specific binding were determined in the absence and presence of 0.2 microM (+)-butaclamol, respectively. Specific binding in normal carotid bodies incubated at near saturating concentrations (0.38 nM) was 1.63 +/- 0.58 pmol/g of tissue. Chronic section of the carotid sinus nerve (14 days) resulted in a 64% reduction (P less than 0.05) in specific binding. We conclude that the majority of specific dopaminergic receptors are located on carotid sinus nerve afferent terminals.