Effect of atrial natriuretic peptide on bronchial tone in anesthetized rabbits.
The effect of atrial natriuretic peptide (ANP) on histamine-induced bronchoconstriction was studied in vivo (in normoxic and in hypoxic rabbits) and in vitro. Thirty-two anesthetized rabbits, spontaneously breathing room air or 10% O2, received infusions of ANP (20, 40, or 80 ng/min/kg normoxia; 20 ng/min/kg hypoxia) or the vehicle for 100 min. After 75 min of ANP infusion, bronchoconstriction was induced inhaling histamine; respiratory resistance (Rrs) was measured prior to and until 20 min posthistamine. The results show that the histamine-induced increase in Rrs was significantly reduced by ANP 80 ng/kg/min in normoxia, and by ANP 20 ng/kg/min in hypoxia. In vitro, ANP had no effect on tracheal and bronchial smooth muscle precontracted with histamine or acetylcholine. These results show that ANP can decrease a histamine-induced bronchoconstriction in vivo but not in vitro, suggesting an indirect mechanism of action.
Robichaud
A
A
Département de pharmacologie, Faculté de Médecine, Université de Montréal, Québec, Canada.
Michoud
M C
MC
Saunier
C
C
Duvivier
C
C
Peslin
R
R
du Souich
P
P
D000403:Airway Resistance / Q000187:drug effects*; D000777:Anesthetics; D000818:Animals; D001249:Asthma / Q000188:drug therapy*; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000494:pharmacology*; D001993:Bronchodilator Agents / Q000097:blood / Q000494:pharmacology*; D004195:Disease Models, Animal; D066298:In Vitro Techniques; D008297:Male; D010100:Oxygen / Q000494:pharmacology; D011817:Rabbits
D000777:Anesthetics; D001993:Bronchodilator Agents; D009320:Atrial Natriuretic Factor; D010100:Oxygen