Stay Connected. Manage Your Care.
Access your health information anytime and anywhere, at home or on the go, with MyHealth.
- Message your clinic
- View your lab results
- Schedule your next appointment
- Pay your bill
The MyHealth mobile app from Stanford Health Care puts all your health information at your fingertips and makes managing your health care simple and quick.
Guest Services
24/7
We are available to assist you
whenever you need it. Give us a call at
650-498-3333 or
PHYSICIAN HELPLINE
Have a question? We're here to help! Call 1-866-742-4811
Monday - Friday, 8 a.m. - 5 p.m.
REFER A PATIENT
Fax 650-320-9443
Track your patients' progress and communicate with Stanford providers conveniently and securely.
Abstract
Adenosine has potent immunosuppressive activity. Since the source of adenosine and the mechanism of its release in the immune system is largely unknown and may vary according to cell type, we have evaluated the relationship between adenosine metabolism and the enzymatic activities and mRNA levels of adenosine-metabolizing enzymes in myeloid and lymphoid cell lines. Induction of HL-60 cell differentiation along the macrophage lineage by PMA resulted in a reduction in the activities of adenosine deaminase (ADA), adenosine kinase (AK), and inosine monophosphate-specific cytosolic 5'-nucleotidase and an elevation of ecto-5'-nucleotidase (ecto-5'-NT). These changes were accompanied by an elevation of ecto-5'-NT mRNA and a decrease in ADA and AK mRNAs in a time-dependent fashion. Comparison of AK and ADA mRNA levels in several other leukemic cell lines revealed generally similar responses to PMA with much stronger suppression in immature T cells than in B cells. The metabolism of adenosine either through phosphorylation (AK) or deamination (ADA) was reduced in PMA-stimulated cells. Furthermore, the cumulative changes in enzyme expression resulted in a 2.5-fold increase in intracellular adenosine formation in PMA-stimulated cells. The inhibition of AK by 5'-iodotubercidin further increased adenosine formation by 6-fold over that in untreated cells. In accord with the increase in ecto-5'-NT activity, extracellular AMP dephosphorylation increased dramatically, but there was no increase in extracellular ATP degradation. These results indicate that a coordinated shift in adenosine-metabolizing enzyme levels during PMA-induced HL-60 cell differentiation is accompanied by a decrease in adenosine uptake and an increase in adenosine release.
View details for Web of Science ID A1997WX98700053
View details for PubMedID 9144513