Pituitary adenylate cyclase activating peptide induces cGMP-mediated relaxation in guinea-pig airways.
The mechanism of relaxation of the guinea-pig trachea induced by pituitary adenylate cyclase activating peptide (PACAP)-27 was investigated. We examined whether modulators of nitric oxide (NO) and carbon monoxide (CO) affect PACAP-induced response of tracheal strips in vitro. Pretreatment with N omega-nitro-L-arginine methyl ester hydrochloride (L-NAME) and L-arginine (L-arg) had no effect, while 1H-[1,2,4] oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), haemoglobin and zinc protoporphyrin IX (ZnPP-9) partially abolished the PACAP-induced relaxation. PACAP-27 elevated cyclic GMP level in airway smooth muscle tissue. These results indicate that PACAP-27 not only induces cyclic AMP-mediated responses, but also cyclic GMP-mediated responses in the airway. In addition, CO is related to the PACAP-induced elevation of cGMP level in the tracheal tissue.
Saotome
M
M
Department of Pulmonary Medicine, University of Tsukuba, Japan.
Uchida
Y
Y
Nomura
A
A
Endo
T
T
Hasegawa
S
S
D000704:Analysis of Variance; D000818:Animals; D002248:Carbon Monoxide / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009479:Neuropeptides / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D014132:Trachea / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology*
D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D014665:Vasodilator Agents; D009569:Nitric Oxide; D002248:Carbon Monoxide; D006152:Cyclic GMP