Exclusion criteria
Animals were excluded with pre-drug mean arterial blood pressure
<60 mmHg (in anaesthetized rats) or <40 mmHg (in
ventilated rabbits); arterial PO2 of <70 mmHg;
arterial PCO2 <25 or >40 mmHg; or
if arrhythmias occurred during the stabilisation phase of the
experiment. In the randomised trials, rats were excluded if they died
prior to the administration of chloroquine in trial (i), or the
intervention in trials (ii) to (vi).