Differential remodeling responses of cerebral and skeletal muscle arterioles in a novel organ culture system

Abstract

Evidence suggests that maladaptive changes in the cerebral microcirculation may contribute to ischemia in numerous diseases. We sought, therefore, to develop an ex vivo organ culture system to study early changes in cerebral arteriolar structure and function, and to compare associated findings to those for non-cerebral arterioles. Pilot studies revealed that rabbit cerebral arterioles maintained contractility longer when cultured in media containing rabbit-specific plasma rather than fetal bovine serum. Cerebral and skeletal muscle arterioles were cultured in a pressure myograph for 5 days; maximum dilatory and contractile responses were measured at 0, 1, 3, and 5 days. Passive properties were preserved in cerebral arterioles over the entire culture period, although skeletal muscle arterioles underwent constrictive remodeling. Cerebral arterioles also maintained a myogenic capability over the entire culture period, albeit at progressively larger diameters, whereas the skeletal muscle arterioles did so only over 3 days. Culture in rabbit serum, which contains numerous growth factors and clotting factors, did not induce or increase inward remodeling in cerebral or skeletal arterioles. These results suggest inherent, organ-specific differences in arteriolar remodeling, and that extensive results in the literature on non-cerebral arterioles should not be extrapolated to predict responses in the cerebral microcirculation.