Effects of spaceflight on vasoconstrictor and mechanical properties of mouse cerebral arteries

Abstract

There is evidence to indicate that cerebral blood flow is diminished in astronauts upon return to Earth. Further, data from ground‐based animal models simulating the effects of microgravity have shown enhanced vasoconstriction and stiffness of cerebral arteries. The purpose of this study was to determine the effects of 13 d spaceflight (STS‐135 shuttle mission) on myogenic vasoconstrictor and mechanical properties of mouse cerebral arteries. Basilar and posterior communicating arteries (PCoA) were harvested and prepared for in vitro experimentation. Myogenic vasoconstrictor responses were lower and vascular distensibility was greater in the basilar arteries of spaceflown mice (n=7) relative to ground control animals (n=12). The elastic properties of the PCoA, as characterized via nanoindentation, demonstrated a 37% reduction in stiffness from spaceflown mice relative to controls. These results demonstrate that spaceflight alters vasoconstrictor and mechanical properties of cerebral arteries and these changes may provide critical insight into the underlying cause of vision impairment in astronauts.Supported by NASA grant NNX09AP06G