Potentiation by neuropeptide Y of histamine H1 receptor-mediated contraction in rat blood vessels.
Histamine-induced contraction and its potentiation by neuropeptide Y were investigated in rat blood vessels. Rat arteries and veins constricted with single concentrations of histamine dose-dependently (0.1-100 microM). This histamine-induced contraction immediately desensitized. Histamine H1 receptor antagonists, 1 microM mepyramine and 1 microM diphenhydramine, abolished this transient contraction completely, whereas cimetidine, phentolamine, reserpine and tetrodotoxin failed to inhibit the contraction. Histamine H1 receptor mRNA level by reverse transcription-polymerase chain reaction was quite parallel to histamine H1 receptor-mediated contraction, indicating that the contraction is mediated through histamine H1 receptors in the smooth muscle. Neuropeptide Y (10 nM in arteries and 3 nM in veins, respectively) significantly potentiated histamine H1 receptor-mediated contraction via neuropeptide Y1 receptors in most of rat blood vessels. Since the phospholipase C inhibitors, neomycin (1 mM) and 2-nitro-4-carboxyphenyl-N, N-diphenylcarbamate (NCDC, 10 microM), respectively, specifically abolished the potentiation, the potentiation by neuropeptide Y may depend on activation of phospholipase C.
Piao
Honglan
H
Division of Pharmacology, Department of Molecular genetics and Signal Transduction Research, Course for Molecular and Cellular Medicine, Niigata University Graduate School of Medical and Dental Sciences, Japan.
Nagai
Shingo
S
Tsurumaki
Tatsuru
T
Niki
Takeshi
T
Higuchi
Hiroshi
H
D000818:Animals; D001158:Arteries / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006632:Histamine / Q000378:metabolism / Q000494:pharmacology*; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009355:Neomycin / Q000494:pharmacology; D009478:Neuropeptide Y / Q000378:metabolism / Q000494:pharmacology*; D048448:Phenylcarbamates / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D043562:Receptors, G-Protein-Coupled / Q000187:drug effects; D011969:Receptors, Histamine H1 / Q000187:drug effects* / Q000378:metabolism; D018013:Receptors, Neuropeptide / Q000187:drug effects; D010738:Type C Phospholipases / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000378:metabolism / Q000494:pharmacology*; D014680:Veins / Q000187:drug effects* / Q000378:metabolism
D004791:Enzyme Inhibitors; D006634:Histamine H1 Antagonists; D009478:Neuropeptide Y; C066211:Npy1r protein, rat; D048448:Phenylcarbamates; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D011969:Receptors, Histamine H1; D018013:Receptors, Neuropeptide; D014662:Vasoconstrictor Agents; C025508:2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate; D006632:Histamine; D010738:Type C Phospholipases; D011738:Pyrilamine; D009355:Neomycin