Differences between cerebrovascular reactivity to L-arginine in the anterior and posterior cerebral circulation.

BACKGROUND

Cerebral endothelial function might be different in distinct cerebrovascular territory, thereby making these areas more susceptible to ischemia and stroke. Higher incidence and prevalence of stroke in males suggest that gender could have a strong influence on this difference. In order to evaluate cerebral endothelial function, we compared cerebrovascular reactivity (CVR) to L-arginine in the anterior and posterior cerebral circulation in healthy young males and females.

METHODS

Thirty healthy subjects, 15 females (32.1 ± 7.1 years) and 15 males (32.2 ± 6.3 years), were included. The mean arterial velocity in the middle cerebral artery (MCA) and the posterior cerebral artery (PCA) was measured by transcranial Doppler sonography before and after intravenous infusion of L-arginine, and CVR to L-arginine was then calculated.

RESULTS

CVR to L-arginine was significantly higher in PCA than in MCA in all subjects (19.2 ± 8.2 vs. 13.6 ± 7.1%, p ≤ 0.01). In addition, CVR to L-arginine was significantly more pronounced in females compared to males in PCA (22.7 ± 8.3 vs. 15.8 ± 6.7%, p ≤ 0.01) and MCA (16.8 ± 6.4 vs. 10.4 ± 6.4%, p < 0.05).

CONCLUSIONS

Lower CVR to L-arginine and therefore lower cerebral endothelial function in the anterior cerebral circulation and in males might be related to the higher incidence of ischemia and stroke in the anterior cerebral circulation, particularly in males.