Evidence of depolarization-induced cAMP increase in the superior cervical ganglion of several mammalian species.

1. The activation of cAMP synthesis resulting from exposure of superior cervical ganglion (SCG) tissue to high K+ solutions observed in calf has been found to occur in three other mammalian species, namely rat, cat, and rabbit. 2. The cAMP accumulation in the ganglion of calf is much less pronounced than that occurring in the other species. The enhancing effect oftheophylline on the increase of cAMP was found to be much greater in the SCG of calf than in that of other species. When veratridine was used as the depolarizing agent the species differences were found to be similar to those observed after potassium stimulation. 3. The effectiveness of several other depolarizing agents in causing an increase in the cAMP level was tested in rabbit SCG.