Neurokinin(3) receptors couple to the activation of neuronal nitric-oxide synthase in stably transfected Chinese hamster ovary cells.
Several physiological effects induced by activation of neurokinin(3) (NK(3)) receptors are mediated by the production of nitric oxide (NO). We investigated the intracellular coupling of NK(3) receptors to NO synthase (NOS) using a Chinese hamster ovary cell line that was stably transfected with both the NK(3) receptor and type I (neuronal) NOS. NOS activity in the transfected cell line was assayed directly, by measuring the formation of L-citrulline, another product of NOS, as well as indirectly, by measuring the production of cGMP in cultured rat fetal lung fibroblasts (RFL-6 cells). MePhe(7)-neurokinin B (NKB) stimulation of L-[(3)H]citrulline production was concentration-dependent and yielded a two-site model for the concentration-response relationship. The production of L-citrulline in response to two other tachykinins, substance P or neurokinin A, revealed only a one-site nature of the response. The production of cGMP in response to MePhe(7)-NKB had an EC(50) value that corresponded to the high-potency component of MePhe(7)-NKB-induced production of L-[(3)H]citrulline. Agonist-induced calcium signaling was also concentration-dependent, and the acute increase in the production of cGMP by MePhe(7)-NKB (0.1 nM) was dependent on the release of calcium from intracellular stores. Results of this study provide the first direct evidence that NK(3) receptors couple to the generation of NO within the same cell.
Linden
D R
DR
Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Chell
M J
MJ
El-Fakahany
E E
EE
Seybold
V S
VS
D000818:Animals; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D002460:Cell Line; D002956:Citrulline / Q000494:pharmacology; D006224:Cricetinae; D006152:Cyclic GMP / Q000096:biosynthesis; D004789:Enzyme Activation / Q000187:drug effects; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007295:Inositol Phosphates / Q000378:metabolism; D015287:Neurokinin B / Q000031:analogs & derivatives / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D018042:Receptors, Neurokinin-3 / Q000187:drug effects / Q000378:metabolism*; D014162:Transfection / Q000235:genetics
D007295:Inositol Phosphates; D010880:Piperidines; D018042:Receptors, Neurokinin-3; C080394:neurokinin B, MePhe(7)-; D002956:Citrulline; D015287:Neurokinin B; C496320:NOS1 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D006162:Guanylate Cyclase; D006152:Cyclic GMP; C091554:SR 142801; D002118:Calcium