Heterogeneity of nucleotide receptors in NG108-15 neuroblastoma and C6 glioma cells for mediating phosphoinositide turnover

J Neurochem. 1994 Feb;62(2):536-42. doi: 10.1046/j.1471-4159.1994.62020536.x.

Abstract

We have compared the characteristics of receptors for nucleotide analogues and the involvement of phospholipase C (PLC) in the effector mechanism in NG108-15 neuroblastoma and C6 glioma cells. The relative potency of these analogues to stimulate inositol phosphate (IP) formation is UTP > UDP >> 2-methylthio-ATP (2-MeSATP), GTP > ATP, CTP > ADP > UMP in NG108-15 cells and ATP > UTP > ADP > GTP > UDP >> 2Me-SATP, CTP, UMP, in C6 glioma cells. alpha, beta-Methylene-ATP, beta, gamma-methylene-ATP, AMP, and adenosine had little or no effect in both types of cells. The EC50 values were 3 and 106 microM for UTP in NG108-15 and C6 glioma cells, respectively. The EC50 value for ATP in C6 glioma cells was 43 microM. 2-MeSATP was threefold more potent than ATP in NG108-15 cells but had little effect in C6 glioma cells at 1 mM. In NCB-20 cells, a similar rank order of potency to that found in NG108-15 cells, i.e., UTP >> GTP > ATP > CTP, was observed. In both NG108-15 and C6 glioma cells, preincubation with ATP or UTP caused a pronounced cross-desensitization of subsequent nucleotide-stimulated IP production. ATP and UTP displayed no additivity in terms of IP formation at maximally effective concentrations. In contrast, endothelin-1, bradykinin, and NaF interacted in an additive manner with either nucleotide in stimulating PI hydrolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Enzyme Activation
  • Glioma / metabolism*
  • Glioma / pathology
  • Neuroblastoma / metabolism*
  • Neuroblastoma / pathology
  • Nucleotides / pharmacology*
  • Pertussis Toxin
  • Phosphatidylinositols / metabolism*
  • Protein Kinase C / metabolism
  • Receptors, Purinergic / metabolism*
  • Tumor Cells, Cultured
  • Type C Phospholipases / metabolism
  • Virulence Factors, Bordetella / pharmacology

Substances

  • Nucleotides
  • Phosphatidylinositols
  • Receptors, Purinergic
  • Virulence Factors, Bordetella
  • Pertussis Toxin
  • Protein Kinase C
  • Type C Phospholipases