Ultrasonically nebulized distilled water prevents exogenous histamine hyperreactivity in Toxocara canis-infected mice.
OBJECTIVE
This study examines the effect of ultrasonically nebulized distilled water inhalation on the systemic histamine hyperreactivity of Toxocara canis-infected mice.


METHODS
Uninfected and T. canis-infected mice received an intravenous sublethal dose of histamine and lethality rates were documented. At 24 days post infection, infected mice received ultrasonically nebulized distilled water inhalation for 1 h. Twenty-four hours later histamine levels were determined in bronchoalveolar lavage fluid as well as histamine lethality and toluidine blue-stained mast cell number in the lung.


RESULTS
T. canis-infected mice showed increased lethality after exposure to histamine in comparison to uninfected mice. Ultrasonically nebulized distilled water inhalation prevented histamine-induced lethality and reduced toluidine blue-stained mast cell numbers in the lung.


CONCLUSIONS
The correlation between decreases in stained mast cells in the lung after ultrasonically nebulized distilled water inhalation and inhibition of histamine-induced lethality in these animals suggests participation of mast cells in the phenomenon and could be helpful in understanding the mechanisms of hyperreactivity during helminth parasite infections.
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, 14040-903, São Paulo, Brazil.
A
A
Sá-Nunes
R M F
RM
Bolzoni
A I
AI
Medeiros
M C
MC
Jamur
C
C
Oliver
M Dias
MD
Baruffi
L H
LH
Faccioli
D000707:Anaphylaxis / Q000139:chemically induced / Q000517:prevention & control; D000818:Animals; D005260:Female; D006632:Histamine / Q000008:administration & dosage* / Q000494:pharmacology*; D006967:Hypersensitivity / Q000150:complications / Q000517:prevention & control*; D007700:Kinetics; D008168:Lung / Q000187:drug effects / Q000469:parasitology / Q000473:pathology; D008407:Mast Cells / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D009330:Nebulizers and Vaporizers; D012701:Serotonin / Q000494:pharmacology; D017166:Toxocara canis / Q000502:physiology*; D014120:Toxocariasis / Q000150:complications* / Q000469:parasitology; D014465:Ultrasonics; D014867:Water / Q000008:administration & dosage* / Q000737:chemistry
D014867:Water; D012701:Serotonin; D006632:Histamine