Inhibition of adenosine 3',5'-monophosphate accumulation and lipolysis by adenosine analogs in human subcutaneous adipocytes.

Lipolysis and cAMP accumulation were inhibited by low concentrations of adenosine and its analogs in human sc adipocytes stimulated by 2 microM DL-isoproterenol. The order of potency of the adenosine analogs tested was N6-(phenylisopropyl)adenosine greater than 2-chloroadenosine greater than 5'-N-ethylcarboxamidoadenosine greater than adenosine greater than 2',5'-dideoxyadenosine greater than 2'-deoxyadenosine. Inosine was without effect. No stimulation of cAMP accumulation by 5'-N-ethylcarboxamidoadenosine was observed. These results strongly suggest the presence of inhibitory adenosine Ri- and P-sites and the absence of stimulatory Ra-sites in human sc adipocytes.