The effect of denervation upon the in vitro incorporation of adenosine-8-3H into 3H-adenine nucleotides in the guinea-pig vas deferens.

After denervation of the guinea-pig vas deferens (1, 2, 4 and 8 days) there is a profound fall in the endogenous levels of adenosine triphosphate (ATP) initially to 54% of control at day 1, with a subsequent rise to 80% by day 8 post-operatively. Theoretically, alterations in the synthetic rate of ATP formation or its utilization could account for the changes in endogenous ATP concentration. These possibilities were evaluated in the present study. Using an in vitro incubation system and adenosine-8-3H as a precursor, experiments demonstrated the feasibility of labeling the synthetic pathway primarily as 3H-AMP, 3H-ADP and 3H-ATP with the latter nucleotide constituting the largest fraction. This incorporation into 3H-nucleotides was linear with time up to 30 min and was dependent on the concentration of adenosine-8-3H used. Studies on the incorporation of adenosine-8-3H at 1, 2, 4 and 8 days after denervation showed no difference in the ability of innervated and denervated vasa deferentia to accumulate total 3H-nucleotides, although there was an alteration in 3H-AMP metabolism in the denervated tissue. Possible explanations for the alteration in 3H-AMP metabolism are discussed. A change in the rate of utilization rather than a change in rate of synthesis, is suggested as an explanation for the alterations in ATP content observed after denervation.