Shear stress and aortic histamine synthesis

Abstract

Aortic histamine-forming capacity (HFC) was examined in relationship to the applied mean shear stress intensity created by pulsatile perfusion of rabbit aortas with platelet-free blood for a 1 h period. Mean shear stress intensities ranged from 22-109 dyn/cm2. A high correlation exists between the shear stress and the HFC which is described by the regression equation y = 0.28x - 6.1, where y = HFC and x = mean shear stress intensity. The rate of histamine formation is sensitive to the applied shear stress, and the histidine decarboxylase system of the aorta may have the potential of serving as a coupling agent between applied hemodynamic stress and resultant alterations in aortic wall resistance to macromolecules. [This stress (i.e., hemodynamic-mediated endothelial cell injury) causes an increase in arterial transmural permeability which is considered an initial event in atherosclerotic pathogenesis.].