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Effect of sodium metabisulphite on bronchial blood flow in conscious sheep: pharmacological modulation
Author(s) -
Nichol G.M.,
Parsons G.H.,
Chung K.F.
Publication year - 1994
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1994.tb14826.x
Subject(s) - sodium , blood flow , chemistry , medicine , pharmacology , organic chemistry
1 Sodium metabisulphite (MBS) can induce bronchoconstriction in patients with asthma. We investigated the effects of MBS aerosol on bronchial blood velocity (V br ) and pulmonary resistance in intubated conscious sheep. 2 Bronchial blood velocity was measured by implanting a 20 MHz ultrasonic Doppler flow probe on the common bronchial branch of the bronchoesophageal artery. 3 Inhaled MBS induced a dose‐dependent, transient increase in V br lasting for a few minutes without any changes in aortic and pulmonary artery pressures. There was some tachyphylaxis of the V br response to successive inhalations of MBS. 4 The cholinoceptor antagonist, ipratropium bromide and the H 1 and H 2 histamine antagonists, chlorpheniramine and cimetidine, had no significant effect on MBS‐induced increase on V br . The loop diuretic, frusemide, and the anti‐inflammatory drug, nedocromil sodium, which both inhibit MBS‐induced bronchoconstriction in patients with asthma, were also without effect. 5 We conclude that MBS induces bronchial vasodilatation in conscious sheep, and that this effect is not dependent on the release of histamine or other mediators, or an activation of cholinergic pathways.