PT  - JOURNAL ARTICLE
AU  - Shigyo, M
AU  - Aizawa, H
AU  - Inoue, H
AU  - Matsumoto, K
AU  - Takata, S
AU  - Hara, N
TI  - Pituitary adenylate cyclase activating peptide regulates neurally mediated airway responses
AID  - 10.1183/09031936.98.12010064
DP  - 1998 Jul 01
TA  - European Respiratory Journal
PG  - 64--70
VI  - 12
IP  - 1
4099  - http://erj.ersjournals.com/content/12/1/64.short
4100  - http://erj.ersjournals.com/content/12/1/64.full
SO  - Eur Respir J1998 Jul 01; 12
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.