Bronchoprotective effects of atrial natriuretic peptide against propranolol-induced bronchoconstriction after allergic reaction in guinea pigs.
OBJECTIVE
To study the effects of intravenous atrial natriuretic peptide (ANP) on antigen-induced bronchoconstriction, propranolol-induced bronchoconstriction (PIB) after antigen challenge, and histamine-induced bronchoconstriction in guinea pigs.


METHODS
Allergic bronchoconstriction was evoked by inhalation of ovalbumin (OA) and PIB was caused when 10 mg/mL of propranolol was inhaled 20 min after OA challenge in passively sensitized and artificially ventilated guinea pigs. 25, 50, 100 and 200 microg/mL of histamine were inhaled for 20 s at 5-min intervals in non-sensitized guinea pigs.


RESULTS
Pretreatment with ANP in doses of 0.1 and 1.0 nmol/kg injected intravenously 15 min after antigen challenge reduced PIB in a dose-dependent manner, and 5 min before antigen challenge significantly attenuated PIB but not antigen-induced bronchoconstriction. Intravenous ANP significantly reduced bronchial responses to increasing concentrations of inhaled histamine in a dose-dependent manner.


CONCLUSIONS
These results suggest that ANP possesses protective effects against propranolol-induced and histamine-induced bronchoconstriction, albeit by a non-specific mechanism in guinea pig in vivo.
Mizuguchi
M
M
The Third Department of Internal Medicine, Kanazawa University School of Medicine, Kanazawa, Japan.
Myo
S
S
Fujimura
M
M
D000485:Allergens / Q000633:toxicity; D000818:Animals; D001249:Asthma / Q000139:chemically induced / Q000517:prevention & control*; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D016084:Bronchoconstriction / Q000187:drug effects*; D001993:Bronchodilator Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006632:Histamine; D007275:Injections, Intravenous; D008297:Male; D009330:Nebulizers and Vaporizers; D010047:Ovalbumin / Q000633:toxicity; D011433:Propranolol / Q000633:toxicity
D000485:Allergens; D001993:Bronchodilator Agents; D006632:Histamine; D009320:Atrial Natriuretic Factor; D010047:Ovalbumin; D011433:Propranolol