Chronic sympathetic denervation increases muscarinic cholinoceptor binding in the rat submaxillary gland

Summary Superior cervical ganglionectomy was found to produce a large decrease in the cocaine-sensitive accumulation of ³H-noradrenaline in the rat sub-maxillary gland, indicating an effective sympathetic denervation. Six weeks after unilateral denervation the muscarinic cholinoceptor binding of ³H-QNB was increased by over 50% compared to the contralateral, innervated gland. There were no differences in the Kd values between the innervated and denervated glands. These results suggest that changes in muscarinic cholinoceptor density might be in part responsible for the postsynaptic supersensitivity to cholinoceptor agonists observed after chronic sympathetic denervation.