Adenosine stimulates phosphate and glucose transport in opossum kidney epithelial cells.
We have examined the effects of adenosine on sodium-coupled phosphate and glucose transport in cultured opossum kidney (OK) cells, a continuous cell line that resembles proximal tubule. Adenosine analogues R-(-)-N6-phenylisopropyladenosine (PIA) and 2',5'-dideoxy-adenosine (DDA) were employed as adenosine A1 receptor and P site-selective agonists, respectively. Sodium-dependent phosphate uptake activity (Na-Pi symport) increased by approximately 25% above both basal and parathyroid hormone (PTH)-inhibited levels in cells treated with PIA (0.1, 1 microM) but not in cells treated with DDA (100 microM). Adenosine (PIA) also stimulated sodium-coupled 3-O-methylglucose transport by approximately 40%. Intracellular adenosine 3',5'-cyclic monophosphate (cAMP) content was inversely related to Na-Pi symport activity in cells treated with PIA and PTH. However, changes in Na-Pi symport activity did not consistently relate to changes in intracellular cAMP. Protein kinase C was activated 15 s after treatment of OK cells with 1 microM PIA. Preincubation of cells with 3 microM staurosporine attenuated the effect of 1 microM PIA on phosphate uptake. These data suggest that Na-Pi and Na-glucose symport activities are stimulated by adenosine acting at a receptor coupled to more than one intracellular signal. It is likely that both protein kinases A and C are involved in these actions of adenosine.
Coulson
R
R
James A. Haley Veterans Hospital, Tampa, Florida 33612.
Johnson
R A
RA
Olsson
R A
RA
Cooper
D R
DR
Scheinman
S J
SJ
D000241:Adenosine / Q000494:pharmacology*; D000621:Aminoisobutyric Acids / Q000493:pharmacokinetics; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology; D002352:Carrier Proteins / Q000187:drug effects; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D016048:Dideoxyadenosine / Q000494:pharmacology; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000493:pharmacokinetics*; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D009893:Opossums / Q000502:physiology*; D010660:Phenylisopropyladenosine / Q000494:pharmacology; D010710:Phosphates / Q000493:pharmacokinetics*; D011493:Protein Kinase C / Q000378:metabolism; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters
D000621:Aminoisobutyric Acids; D002352:Carrier Proteins; D010710:Phosphates; D050608:Sodium-Phosphate Cotransporter Proteins; D027981:Symporters; D010660:Phenylisopropyladenosine; D002110:Caffeine; D016048:Dideoxyadenosine; D000242:Cyclic AMP; D011493:Protein Kinase C; D005947:Glucose; D000241:Adenosine