Background Perinatal hypoxia–ischaemia remains the most important cause of brain injury in the newborn. Marijuana and related cannabinoids have been proposed as treatments for different medical disorders. WIN55212-2 is a synthetic cannabinoid with a neuroprotective potential but its haemodynamic effect has not been extensively studied.

Aim To determine the effects of two WIN55212-2 doses on cardiovascular profile and carotid blood flow in preterm lambs with perinatal asphyxia.

Methods 20 preterm lambs (80–90% GE) were used. Lambs were randomly assigned to receive intravenous WIN55212-2 (100 or 0.01 μg/kg) or not (sham) after hypoxic–ischaemic injury induced by partial cord clamping. A non-injured group was used as control. Carotid blood flow, systemic arterial pressure (SAP), heart rate (HR) and gas exchange were measured at fetal point, at the end of hypoxic–ischaemic injury and during neonatal life. Analysis of variance, p<0.05.

Results After injury, injured groups developed acidosis, hypoxia and hypercapnia in comparison with the control group. Also, they demonstrated an increase in HR without change on SAP. The WIN 100 μg/kg group showed continuous deterioration of gas exchange and SAP during the first 60 minutes of neonatal life in comparison with the other groups (see table).

Conclusion In our model of perinatal asphyxia induced by partial cord occlusion in premature lambs, the administration of higher doses of WIN55212-2 produced transient hypotension with a cerebrovascular vasodilation. Histological analysis must be done to confirm its neuroprotective effect.

FIS06/0839-GV2006111020, FIS07/0733-GV2007111046.