TY - JOUR
T1 - Pituitary adenylate cyclase activating peptide regulates neurally mediated airway responses
AU - Shigyo, M.
AU - Aizawa, H.
AU - Inoue, H.
AU - Matsumoto, K.
AU - Takata, S.
AU - Hara, N.
PY - 1998/7
Y1 - 1998/7
N2 - To clarify the protective effects of pituitary adenylate cyclase activating peptide (PACAP) on airway narrowing, we examined the effects of PACAP on smooth muscle contraction and plasma extravasation in guinea-pig airways. Smooth muscle contraction evoked by electrical field stimulation (EFS) or exogenously applied acetylcholine (ACh) or substance P (SP) was measured before and after PACAP in vitro. The effect of PACAP on airway plasma extravasation was also measured in vivo. In trachea, PACAP (10-9-10-7 M) significantly suppressed smooth muscle contraction evoked by EFS without affecting ACh sensitivity, suggesting that PACAP inhibits cholinergic neuroeffector transmission. In the main bronchi, PACAP (10-9-10-8 M) significantly suppressed the contraction evoked by EFS without affecting SP sensitivity in the presence of atropine, suggesting that PACAP inhibits SP release from excitatory nonadrenergic noncholinergic (eNANC) nerves. In animals treated with atropine and propranolol, PACAP attenuated the increase in plasma extravasation induced by electrical vagus stimulation or by SP. These results suggest that pituitary adenylate cyclase activating peptide may play a role in modulation of airway responses through inhibition of cholinergic and noncholinergic mechanisms.
AB - To clarify the protective effects of pituitary adenylate cyclase activating peptide (PACAP) on airway narrowing, we examined the effects of PACAP on smooth muscle contraction and plasma extravasation in guinea-pig airways. Smooth muscle contraction evoked by electrical field stimulation (EFS) or exogenously applied acetylcholine (ACh) or substance P (SP) was measured before and after PACAP in vitro. The effect of PACAP on airway plasma extravasation was also measured in vivo. In trachea, PACAP (10-9-10-7 M) significantly suppressed smooth muscle contraction evoked by EFS without affecting ACh sensitivity, suggesting that PACAP inhibits cholinergic neuroeffector transmission. In the main bronchi, PACAP (10-9-10-8 M) significantly suppressed the contraction evoked by EFS without affecting SP sensitivity in the presence of atropine, suggesting that PACAP inhibits SP release from excitatory nonadrenergic noncholinergic (eNANC) nerves. In animals treated with atropine and propranolol, PACAP attenuated the increase in plasma extravasation induced by electrical vagus stimulation or by SP. These results suggest that pituitary adenylate cyclase activating peptide may play a role in modulation of airway responses through inhibition of cholinergic and noncholinergic mechanisms.
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U2 - 10.1183/09031936.98.12010064
DO - 10.1183/09031936.98.12010064
M3 - Article
C2 - 9701416
AN - SCOPUS:0031866806
VL - 12
SP - 64
EP - 70
JO - Scandinavian Journal of Respiratory Diseases
JF - Scandinavian Journal of Respiratory Diseases
SN - 0903-1936
IS - 1
ER -