[Exogeneous adenosine triphosphate promotes proliferation of renal tubular epithelial cells].
OBJECTIVE
To investigate the effect of exogeneous ATP on proliferation of renal tubular epithelial cells (LLC-PK1) and its intracellular mechanisms.


METHODS
DNA synthesis was measured by 3H-thymindine incorporation, and proliferation was assessed by cell counting. MAP kinase activity was detected by phosphorylate specific substrate MBP.


RESULTS
Exogeneous ATP (1-1000 mumol/L) significantly increased 3H-TdR uptake in a concentration dependent manner. It also increased cells proliferation. 100 mumol/L ATP rapidly activated MAP kinase. The potency of LLC-PK1 proliferation stimulated by ATP was similar to the effect of polypeptide growth factor EGF. Adenosine was less stimulatory effective than ATP. NBTI (50 mumol/L), an inhibitor of memberous nucleotide transportor, did not reduce the effects of ATP or Ado on proliferation of these cells.


CONCLUSIONS
Extracellular ATP is a potent mitogen of LLC-PK1 cells, and may promote stimulatory effect of EGF in these cells. This mitogenic effect is unlikely induced by ATP entering cells, but may be mediated by purinergic receptors which activate signaling pathway through MAP kinase cascade.
Renal Division, First Teaching Hospital, Beijing.
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Cheng
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Li
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D016228:Endothelial Growth Factors / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology*; D007684:Kidney Tubules / Q000166:cytology*; D013552:Swine
D016228:Endothelial Growth Factors; D000255:Adenosine Triphosphate; D004247:DNA; D017871:Calcium-Calmodulin-Dependent Protein Kinases