Adenosine receptors on human leukocytes IV. characterization of an A1/Ri receptor

Gianni Marone, Rosaria Petracca, Sergio Vigorita, Arturo Genovese, Vincenzo Casolaro

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Adenosine (10-9-10-6 mol/l) and R-phenylisopropyladenosine (10-9-10-7 mol/l) partially inhibited the intracellular accumulation of cyclic AMP induced by isoproterenol, prostaglandin E1, histamine and 5′-N-ethylcarboxamidoadenosine in lymphocytes. In contrast, S-phenylisopropyladenosine, which is a poor agonist of the adenosine A1/Ri receptor, had essentially no inhibitory effect. 8-Phenyltheophylline, in low concentrations that do not inhibit cyclic AMP phosphodiesterase, completely blocked the inhibitory effect of R-phenylisopropyladenosine on the increase in cyclic AMP induced by prostaglandin E1. R-Phenylisopropyladenosine (10-8-10-6 mol/l) also inhibited the cyclic AMP accumulation in lymphocytes induced by forskolin (10-5 mol/l), which activates adenylate cyclase through direct interaction with the enzyme. We also investigated the presence of the adenosine A1/Ri receptor on human polymorphonuclear leukocytes. R-Phenylisopropyladenosine (3×10-9-10-7 mol/l) abolished the stimulating effects of prostaglandin and forskolin on cyclic AMP accumulation in polymorphonuclear leukocytes. This effect was blocked by 8-phenyltheophylline and was not observed with the stereoisomer S-phenylisopropyladenosine. The results support the existence of an A1/Ri receptor that regulates cyclic AMP metabolism of human lymphocytes and polymorphonuclear leukocytes.

Original languageEnglish (US)
Pages (from-to)235-242
Number of pages8
JournalInternational Journal of Clinical and Laboratory Research
Issue number1-4
StatePublished - Mar 1992
Externally publishedYes


  • A/R receptor
  • Adenosine
  • Cyclic AMP
  • Lymphocytes
  • Polymorphonuclear leukocytes

ASJC Scopus subject areas

  • Clinical Biochemistry


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