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.