The disappearance of dopamine-beta-hydroxylase from the rat salivary glands after extirpation of the superior cervical ganglion.

The dopamine-beta-hydroxylase (DBH) activity in the rat salivary glands was followed after ganglionectomy. The results were compared with the corresponding noradrenaline (NA) values from an earlier study. The extraneuronal DBH fraction was 39 per cent of the total DBH activity and remained constant for 2 weeks. The neuronal DBH fraction disappeared almost as fast as NA from the tissue during degeneration. The DBH activity disappeared faster when the axonal stump at axotomy was short than when it was about 2 cm longer, in agreement with an earlier found pattern for NA. There appeared to be no marked "trapping" in the tissue of DBH "released" from the degenerating adrenergic neurons, even though NA disappeared somewhat faster than DBH. No signs of inactivation of DBH in the glands were observed. On the other hand, overflow of DBH to the blood, reflected as increased blood levels, was not found during the period of nerve degeneration.