Isometric contraction of microvascular pericytes from mouse brain parenchyma.

Pericytes were isolated and cultured from mouse cerebroparenchymal microvessels. A single pericyte clone was three-dimensionally cultured in a collagen gel by adding tensile stress, resulting in the reconstruction of narrow stringy fibers. When the contractility of these fibers was evaluated isometrically, they contracted in response to acetylcholine (ACh)1 or noradrenaline; this was accompanied by an increase in intracellular calcium concentration ([Ca(2+)]i). The fibers that were pre-contracted by ACh were completely relaxed by papaverine, which is a smooth-muscle relaxant. Moreover, the muscarinic ACh receptor-antagonist atropine depressed the [Ca(2+)]i response that was induced by ACh. This study demonstrates for the first time the quantitative measurement of the contractions produced by cultured microvascular pericytes from mouse brain parenchyma.