Role of vanilloid receptors in the capsaicin-mediated induction of iNOS in PC12 cells.
The vanilloid receptor 1(VR1) is a nonselective cation channel that is activated by pungent vanilloid compound, extracellular protons, or noxious heat. mRNA of VR1 and vanilloid receptor 1-like receptor (VRL1) were expressed in PC12 cells, and only VRI mRNA was detected in glioma and A10 cell lines. VRI protein was demonstrated in PC12 cells by immunocytochemistry and Western blotting. Capsaicin (CPS), the VRI receptor agonist, led to an increase in intracellular calcium ion, and this effect was blocked by pretreatment with VR1 receptor antagonist capsazepin (CPZ). Treatment of PC12 cells with low concentration of CPS (5-50 microM) increased reactive oxygen species (ROS) production, and inducible nitric oxide synthase (iNOS) was expressed after CPS treatment for 24 h. These CPS-induced changes are inhibited by pretreatment of CPZ. These findings suggest that CPS-induced iNOS expression through the VR1 and/or VRL1-mediated pathway, and this may explain the CPS-mediated physiological and pathological effects in neuron system.
Qiao
Shanlou
S
Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Aichi, Japan. qiaosl@aichi-med-u.ac.jp
Li
Weihua
W
Tsubouchi
Ryoko
R
Murakami
Keiko
K
Yoshino
Masataka
M
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D017931:DNA Primers; D004790:Enzyme Induction; D051379:Mice; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D016716:PC12 Cells; D051381:Rats; D017382:Reactive Oxygen Species; D011955:Receptors, Drug / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D017382:Reactive Oxygen Species; D011955:Receptors, Drug; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; C496321:Nos1 protein, mouse; C496322:Nos1 protein, rat; C496317:Nos2 protein, mouse; C496318:Nos2 protein, rat; D002211:Capsaicin; D002118:Calcium