Receptor-mediated mitogenic effects of substance P on cultured smooth muscle cells.
The neuropeptide substance P, a known mitogen for human blood T-lymphocytes, now is shown to stimulate proliferation of embryonic rat aortic smooth muscle cells of the A7r5 line, at concentrations of 10(-9) M to 10(-6) M. Neurotensin (NT), that has vascular and smooth muscle activity similar to SP, failed to induce proliferation of A7r5 cells. At proliferation-enhancing concentrations, SP increased the concentration of cytosolic Ca2+ in A7r5 cells, suggesting activation of the phosphatidylinositol pathway. Binding of [125I]-substance P to A7r5 cells reached equilibrium rapidly at 4 degrees C, and was saturable, implying that the activation of smooth muscle cells by SP is a receptor-mediated process.
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Payan
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D008938:Mitosis / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects*; D051381:Rats; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000502:physiology*; D013373:Substance P / Q000494:pharmacology*
D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D013373:Substance P; D002118:Calcium