Effect of purines on epinephrine-induced lipolysis in adipose tissue.

The purine bases hypoxanthine, xanthine, guanine, and purine markedly inhibit epinephrine-induced lipolysis in rat adipose tissue, an action previously ascribed only to nucleosides, nucleotides, and nucleic acids. The inhibition by purines and purine conjugates is associated with increased destruction of epinephrine. Allopurinol, an inhibitor of xanthine oxidase, prevents the degradation of epinephrine and prevents or reduces the inhibition of lipolysis. The stimulatory effect of some purine bases on epinephrineinduced lipolysis is confirmed, and the stimulatory effect is shown to occur in human adipose tissue and in tissue of hypophysectomized and thyroidectomized rats.