Neurogenic vasodilation in the rat nasal mucosa involves neurokinin1 tachykinin receptors.
We studied the role of different tachykinin receptors in mediating neurogenic vasodilation in the nasal mucosa of anesthetized pathogen-free rats. Three successive determinations of blood flow were made by injecting radionuclide-labeled microspheres suspended in 70% dextrose into the left ventricle. A selective agonist of the tachykinin NK1 receptor increased nasal blood flow, but neurokinin NK2- and NK3-selective agonists were without effect. The natural agonist of NK1 receptors, substance P (1 microgram/kg), increased nasal blood flow, an effect that was abolished by the selective NK1 receptor antagonist (+)-(2S,3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine (CP-99,994). Capsaicin (25 micrograms/kg), a drug that releases tachykinins from sensory nerves, increased nasal blood flow, and this effect was significantly reduced by CP-99,994. We conclude that a significant component of neurogenic vasodilation in rat nasal mucosa is due to the stimulation of NK1 tachykinin receptors.
Piedimonte
G
G
Cardiovascular Research Institute, University of California, San Francisco.
Hoffman
J I
JI
Husseini
W K
WK
Bertrand
C
C
Snider
R M
RM
Desai
M C
MC
Petersson
G
G
Nadel
J A
JA
D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D008297:Male; D009475:Neurons, Afferent / Q000378:metabolism; D009831:Olfactory Mucosa / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D011916:Rats, Inbred F344; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*; D018039:Receptors, Tachykinin; D013373:Substance P / Q000494:pharmacology; D015320:Tachykinins / Q000378:metabolism*; D014664:Vasodilation
D010880:Piperidines; D017981:Receptors, Neurotransmitter; D018039:Receptors, Tachykinin; D015320:Tachykinins; C080755:3-(2-methoxybenzylamino)-2-phenylpiperidine; D013373:Substance P; D002211:Capsaicin