Degeneration secretion of saliva in the rat following sympathectomy.

1. After previous extirpation of the superior cervical ganglion saliva was found to flow from the cannulated submaxillary duct of rats under chloralose anaesthesia. The secretion started 13-14.5 hr after sympathectomy, increased gradually in rate and then slowed down and ceased, lasting for about 12 hr.2. Injection of alpha- or beta-adrenoreceptor blocking drugs reduced the flow and a combination of both types of drugs abolished it. It is concluded that the secretion was caused by noradrenaline released from the degenerating nerves, and that the phenomenon is an example of the degeneration activity described in other preparations as an effect of section of post-ganglionic autonomic nerves.3. A similar, but less pronounced, secretion was found in the parotid gland of the rat.