Neurokinin A as a potent bronchoconstrictor.
Neurokinin A (NKA) and B (NKB) were more potent bronchoconstrictive agents than substance P (SP) in guinea pig tracheal strips. The content of NKA in guinea pig lung homogenate was 2.26 +/- 1.09 pmol/g wet lung, which was approximately half that of SP (4.46 +/- 1.33 pmol/g wet lung); NKB was not detected in the guinea pig lung homogenate (less than 0.01 pmol/g wet lung). Histologically, NKA-immunoreactive fibers were distributed in the bronchial smooth muscle layers. Pulmonary arteries and veins were also found to be innervated by NKA-immunoreactive nerves. In addition, a few fibers were observed in the trachea, bronchioles, and alveoli. These findings suggest that NKA may be one of the neurotransmitters of the noncholinergic bronchoconstrictive nerves.
Uchida
Y
Y
Nomura
A
A
Ohtsuka
M
M
Hasegawa
S
S
Goto
K
K
Kimura
S
S
Sugita
Y
Y
Uchiyama
Y
Y
D000818:Animals; D001980:Bronchi / Q000187:drug effects* / Q000294:innervation; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D008168:Lung / Q000032:analysis; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D015288:Neurokinin A; D015287:Neurokinin B; D009479:Neuropeptides / Q000032:analysis / Q000494:pharmacology*; D011863:Radioimmunoassay
D009479:Neuropeptides; D015288:Neurokinin A; D015287:Neurokinin B