Assay of cyclic 3'-5'-monophosphate in the regenerating forelimb of the newt, Triturus.

The cyclic adenosine 3′-5′-monophosphate content of four regenerate stages in the forelimb of the newt, Triturus viridescens, was assayed using the Gilman method and compared to the content in the normal, unamputated, forelimb. The concentration was found to be highest in the earliest stages of regeneration, followed by a sharp drop and then a rise to a plateau approximately that of the unamputated limb. The possibility that cyclic AMP acts as a second messenger for nervous and hormonal influences on regeneration is discussed.