αCGRP-Induced Changes in Cerebral and Systemic Circulation; A TCD Study

Abstract

It is known that perivascular application of CGRP induces cerebral vasodilatation. However, it is unclear whether intravenous alfa CGRP (alpha CGRP) induces changes in cerebral and systemic hemodynamics. Therefore, we studied the influence of an alpha CGRP intravenous infusion at a rate of 1.5 mcg/min in 20 min on mean arterial velocity in the middle cerebral artery (vm MCA) and in the posterior cerebral artery (vm PCA) in twenty healthy subjects using transcranial Doppler (TCD). We found out that alpha CGRP decreased vm MCA (p < 0.001), vm PCA (p < 0.001), mean arterial pressure (MAP) (p < 0.001) and end-tidal CO2 (Et-CO2) (p = 0.030). The heart rate (HR) increased during alpha CGRP infusion (p < 0.001). In addition, we found a positive relationship between Et-CO2 and vm MCA (p = 0.001) as well as vm PCA (p = 0.043). In our view, alpha CGRP induces changes in cerebral and systemic circulation in healthy volunteers. It might cause vasodilatation of MCA and PCA and a compensatory decrease of Et-CO2 to alpha CGRP related hemodynamic changes.