Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

We have examined the effect of methylene blue 4mg kg-1 on the pulmonary vasodilator action of inhaled nitric oxide (8, 32, 128 and 512 volumes per million) in nine sheep with pulmonary hypertension induced by hypoxia (FlO2 = 0.12). The dose-response to nitric oxide was unchanged by methylene blue, but increased cardiac output was noted (P < 0.01). These results indicate that methylene blue may not inhibit the action of nitric oxide on guanylate cyclase, as suggested previously, and that treatment of methaemoglobinaemia occurring during therapeutic inhalation of nitric oxide with methylene blue may not block the vasodilator effect of nitric oxide on the pulmonary vasculature.


Journal article


Br J Anaesth

Publication Date





511 - 516


Animals, Blood Pressure, Dose-Response Relationship, Drug, Female, Hemodynamics, Hypertension, Pulmonary, Hypoxia, Methylene Blue, Nitric Oxide, Pulmonary Artery, Pulmonary Circulation, Sheep, Vasodilation