Neurokinin A-(4-10): a potent bronchospastic agent virtually devoid of sialologic properties in anaesthetized guinea-pigs.
The ability of substance P, neurokinin A and its C-terminal fragment, neurokinin A-(4-10), to elicit NK-1 (salivation) and NK-2 (bronchospasm) receptor-mediated responses was investigated in anaesthetized guinea-pigs. Neurokinin A-(4-10) produced a dose-related increase in tracheal insufflation pressure and its maximal effect was similar to that elicited by neurokinin A and significantly greater than that of substance P. On the other hand substance P induced a potent dose-dependent increase of salivation while neurokinin A was significantly less potent. Neurokinin A-(4-10) did not exert any sialologic effect even at the dose of 100 nM/kg. These findings indicate that neurokinin A-(4-10) might be a valuable pharmacological tool for characterizing the involvement of NK-1 and NK-2 receptors in physiological responses in vivo.
Manzini
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S
Istituto Farmacobiologico Malesci S.p.A., Pharmacology Department, Florence, Italy.
Conti
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S
Maggi
C A
CA
Rovero
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P
Ballati
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L
D000758:Anesthesia; D000818:Animals; D001986:Bronchial Spasm / Q000139:chemically induced*; D006168:Guinea Pigs; D008297:Male; D015288:Neurokinin A; D009479:Neuropeptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter / Q000032:analysis*; D012472:Salivation / Q000187:drug effects*; D013373:Substance P / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects
D009479:Neuropeptides; D010446:Peptide Fragments; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter; D013373:Substance P; D015288:Neurokinin A; C056408:neurokinin A(4-10)