TY - JOUR
T1 - N-Arachidonyl dopamine sensitizes rat capsaicin-sensitive lung vagal afferents via activation of TRPV1 receptors
AU - Hsu, Chun-Chun
AU - Bien, Mauo-Ying
AU - Huang, Ya-Tien
AU - Ruan, Ting
AU - Kou, Yu-Ru
AU - Lin, You-Shuei
PY - 2009/7/31
Y1 - 2009/7/31
N2 - We investigated the effect of N-arachidonyl dopamine (NADA), an endogenous agonist of both transient receptor potential vanilloid 1 (TRPV1) and cannabinoid CB1 receptors, on the sensitivity of rat capsaicin-sensitive lung vagal afferent (CSLVA) fibers. In artificially ventilated rats, an intravenous infusion of NADA (400 μg/kg/ml, 0.5 ml/min for 2 min) mildly elevated the baseline CSLVA fiber activity, whereas it markedly potentiated CSLVA fiber responses to a right atrial injection of capsaicin or adenosine, and to lung inflation. The potentiating effect on CSLVA fiber sensitivity to an adenosine injection or lung inflation was blocked by capsazepine pretreatment (a TRPV1 receptor antagonist), but was unaffected by AM251 pretreatment (a CB1 receptor antagonist). In spontaneously breathing rats, a NADA infusion similarly potentiated the CSLVA fiber-mediated apneic response evoked by an adenosine injection, and this potentiating effect was also prevented by capsazepine pretreatment. We concluded that NADA at the dose tested non-specifically increases CSLVA fiber sensitivity to chemical and mechanical stimulation via activation of TRPV1 receptors.
AB - We investigated the effect of N-arachidonyl dopamine (NADA), an endogenous agonist of both transient receptor potential vanilloid 1 (TRPV1) and cannabinoid CB1 receptors, on the sensitivity of rat capsaicin-sensitive lung vagal afferent (CSLVA) fibers. In artificially ventilated rats, an intravenous infusion of NADA (400 μg/kg/ml, 0.5 ml/min for 2 min) mildly elevated the baseline CSLVA fiber activity, whereas it markedly potentiated CSLVA fiber responses to a right atrial injection of capsaicin or adenosine, and to lung inflation. The potentiating effect on CSLVA fiber sensitivity to an adenosine injection or lung inflation was blocked by capsazepine pretreatment (a TRPV1 receptor antagonist), but was unaffected by AM251 pretreatment (a CB1 receptor antagonist). In spontaneously breathing rats, a NADA infusion similarly potentiated the CSLVA fiber-mediated apneic response evoked by an adenosine injection, and this potentiating effect was also prevented by capsazepine pretreatment. We concluded that NADA at the dose tested non-specifically increases CSLVA fiber sensitivity to chemical and mechanical stimulation via activation of TRPV1 receptors.
KW - Afferent sensitization
KW - Lung
KW - Lung vagal C fibers
KW - NADA
KW - TRPV1 receptors
UR - http://www.scopus.com/inward/record.url?scp=67651100709&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67651100709&partnerID=8YFLogxK
U2 - 10.1016/j.resp.2009.06.007
DO - 10.1016/j.resp.2009.06.007
M3 - Article
C2 - 19539789
AN - SCOPUS:67651100709
VL - 167
SP - 323
EP - 332
JO - Respiratory Physiology and Neurobiology
JF - Respiratory Physiology and Neurobiology
SN - 1569-9048
IS - 3
ER -