Strain-related differences in Sephadex bead-induced airway hyperresponsiveness and inflammation in rats.
OBJECTIVE
The aim of this study was to compare Sephadex G-200 (Sephadex)-induced airway hyperresponsiveness (AHR) and pulmonary eosinophilia among some rat strains.


METHODS
Sprague-Dawley (SD), Brown-Norway (BN), Fischer 344 (Fischer), Lewis and Wistar-Kyoto (WKY) rats were used.


METHODS
Sephadex (0.5 mg/animal) was intravenously administered on days 0, 2 and 5. Measurement of AHR using serotonin and bronchoalveolar lavage (BAL) was performed on day 7.


RESULTS
The Lewis strain exhibited significant AHR to Sephadex but the BN, Fischer and WKY strains did not. Additionally, the degree of AHR in Lewis rats was smaller than in SD rats throughout the study. Eosinophils in BAL fluid, however, increased in each strain, and the magnitude of the response was BN > Lewis > WKY > Fischer. Both the AHR and pulmonary eosinophilia in Lewis rats were inhibited by dexamethasone (0.1 mg/kg, p.o. x3).


CONCLUSIONS
These results indicate that the Lewis rat is a useful strain for analysis of the mechanism of Sephadex-induced AHR and airway inflammation.
Matsubara
S
S
Lead Optimization Research Laboratory, Tanabe Seiyaku Co. Ltd., Saitama, Japan.
Nakata
A
A
Kikuchi
M
M
Kikkawa
H
H
Ikezawa
K
K
Naito
K
K
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D003907:Dexamethasone / Q000627:therapeutic use; D003911:Dextrans; D004802:Eosinophilia / Q000139:chemically induced / Q000473:pathology; D004804:Eosinophils / Q000473:pathology; D007958:Leukocyte Count; D008171:Lung Diseases / Q000139:chemically induced / Q000473:pathology; D008297:Male; D008863:Microspheres; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D011921:Rats, Inbred WKY; D012130:Respiratory Hypersensitivity / Q000139:chemically induced* / Q000517:prevention & control; D013045:Species Specificity
D000893:Anti-Inflammatory Agents; D003911:Dextrans; D003907:Dexamethasone; C025614:sephadex