Functional substance P receptors on a human astrocytoma cell line (U-373 MG).
[125I]Bolton Hunter conjugate of substance P ([125I]BHSP) can bind to human astrocytoma membranes in a monophasic and saturable manner with a Kd of 0.57 +/- 0.17 nM and a Bmax of 67.8 +/- 5.5 fmol/mg protein. The rank order of potency of tachykinins and related analogues as inhibitors of [125I]BHSP binding to astrocytoma membranes and intact cells correlated with their relative abilities to stimulate uridine incorporation into nucleic acid. The observed specificity pattern conformed to that reported for the NK1 tachykinin receptor with SP much greater than eledoisin greater than neurokinin A greater than neurokinin B and [Glp6, L-Pro9]SP(6-11) much greater than [Glp6, D-Pro9]SP(6-11).
Lee
C M
CM
Department of Biochemistry, Faculty of Medicine, Chinese University of Hong Kong.
Kum
W
W
Cockram
C S
CS
Teoh
R
R
Young
J D
JD
D001254:Astrocytoma; D001667:Binding, Competitive; D002460:Cell Line; D006165:Guanylyl Imidodiphosphate / Q000378:metabolism; D006801:Humans; D009696:Nucleic Acids / Q000378:metabolism; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000378:metabolism / Q000502:physiology*; D015320:Tachykinins / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000378:metabolism*
D009696:Nucleic Acids; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D015320:Tachykinins; D006165:Guanylyl Imidodiphosphate