Characterization of binding sites for the angiotensin II antagonist 125I-[Sarc1,Ile8]-angiotensin II on murine neuroblastoma N1E-115 cells.
The murine neuroblastoma N1E-115 cell line contains binding sites for the angiotensin II (Ang II) receptor antagonist 125I-[Sarc1,Ile8]-Ang II (125I-SARILE). Binding of 125I-SARILE to N1E-115 membranes was rapid, reversible, and specific for Ang II-related peptides. The rank order potency of 125I-SARILE binding was the following: [Sarc1]-Ang II = [Sarc1,Ile8]-Ang II greater than Ang II greater than Ang III = [Sarc1,Thr8]-Ang II much greater than Ang I. Scatchard analysis of membranes prepared from confluent monolayers revealed a homogenous population of high affinity (KD = 383 +/- 60 pM) binding sites with a Bmax of 25.4 +/- 1.6 fmol/mg of protein. Moreover, the density, but not the affinity, of the binding sites increased as the cells progressed from logarithmic to stationary growth in culture. Finally, agonist, but not antagonist, binding to N1E-115 cells was regulated by guanine nucleotides. Collectively, these results suggest that the murine neuroblastoma N1E-115 cell line may provide a useful model in which to investigate the signal transduction mechanisms utilized by neuronal Ang II receptors.
Fluharty
S J
SJ
Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104.
Reagan
L P
LP
D015059:1-Sarcosine-8-Isoleucine Angiotensin II / Q000378:metabolism*; D000803:Angiotensin I / Q000378:metabolism; D000804:Angiotensin II / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000805:Angiotensin III / Q000378:metabolism; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001667:Binding, Competitive; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism*; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D057911:Angiotensin Receptor Antagonists; D011945:Receptors, Angiotensin; D000804:Angiotensin II; D000805:Angiotensin III; D006165:Guanylyl Imidodiphosphate; C014805:angiotensin II, Sar(1)-Thr(8)-; D000803:Angiotensin I; D015059:1-Sarcosine-8-Isoleucine Angiotensin II