title: Role of nitric oxide in hyperpnea-induced bronchoconstriction and airway microvascular permeability in guinea pigs.
abstract: The present study aimed to evaluate the role of nitric oxide (NO) on hyperpnea-induced bronchoconstriction (HIB) and airway microvascular hyperpermeability (AMP). Sixty-four guinea pigs were anesthetized, tracheotomized, cannulated, and connected to animal ventilator to obtain pulmonary baseline respiratory system resistance (Rrs). Animals were then submitted to 5 minutes hyperpnea and Rrs was evaluated during 15 minutes after hyperpnea. AMP was evaluated by Evans blue dye (25 mg/kg) extravasation in airway tissues. Constitutive and inductible NO was evaluated by pretreating animals with N(G)-nitro-L-arginine methyl ester (L-NAME) (50 mg/kg), aminoguadinine (AG) (50 mg/kg), and L-arginine (100 mg/kg) and exhaled NO (NOex) was evaluated before and after drug administration and hyperpnea. The results show that L-NAME potentiated (57%) HIB and this effect was totally reversed by L-arginine pretreatment, whereas AG did not have effect on HIB. L-NAME decreased basal AMP (48%), but neither L-NAME nor AG had any effect on hyperpnea-induced AMP. NOex levels were decreased by 50% with L-NAME, effect that was reversed by L-arginine treatment. These results suggest that constitutive but not inducible NO could have a bronchoprotective effect on HIB in guinea pigs. The authors also observed that neither constitutive nor inducible NO seems to have any effect on hyperpnea-induced AMP.
authors.affiliation: Department of Physical Therapy, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Pennacchioni-Alves
authors.forename: Rodolfo Paula
authors.initials: RP
authors.lastname: Vieira
authors.forename: Fernanda Degobi Tenório Quirino
authors.initials: FD
authors.lastname: Santos Lopes
authors.forename: Fernanda Magalhaes
authors.initials: FM
authors.lastname: Arantes-Costa
authors.forename: Fabia B
authors.initials: FB
authors.lastname: Pianheri
authors.forename: Milton Arruda
authors.initials: MA
authors.lastname: Martins
authors.forename: Celso Ricardo
authors.initials: CR
authors.lastname: Fernandes Carvalho
mesh_terms: D000818:Animals; D001944:Breath Tests; D016084:Bronchoconstriction; D002199:Capillary Permeability / Q000187:drug effects; D006168:Guinea Pigs; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000032:analysis / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011897:Random Allocation; D012121:Respiration, Artificial
chemical_list: D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester