Bronchoconstrictive properties and potentiating effect on bronchial responsiveness of inhaled thromboxane A2 analogue (STA2) in guinea pigs.
Effect of subthreshold concentration of inhaled STA2, a thromboxane A2 (TXA2) analogue, on bronchial responsiveness to histamine was investigated in anesthetized and artificially ventilated guinea pigs. Percent increase in pressure of the airway opening (Pao) by aerosol histamine (50, 100 micrograms/ml) was significantly potentiated by subthreshold dose of aerosol STA2 (0.10 micrograms/ml) which was determined by dose-response curve of % increase in Pao by inhaled STA2 (0.033, 0.10, 0.33, 1.0 micrograms/ml). These results demonstrated that thromboxane A2 could contribute to bronchial hyperresponsiveness which is one of the major clinical features of bronchial asthma.
Fujimura
M
M
Third Department of Internal Medicine, Kanasawa University School of Medicine, Japan.
Saito
M
M
Kurashima
K
K
Miyake
Y
Y
Sakamoto
S
S
Matsuda
T
T
D000336:Aerosols; D000818:Animals; D001980:Bronchi / Q000187:drug effects* / Q000503:physiopathology; D016085:Bronchoconstrictor Agents / Q000494:pharmacology*; D004056:Differential Threshold; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D008297:Male; D013928:Thromboxane A2 / Q000031:analogs & derivatives* / Q000494:pharmacology
D000336:Aerosols; D016085:Bronchoconstrictor Agents; D013928:Thromboxane A2; C037866:STA 2