Smooth muscle contraction is the fundamental event in gastrointestinal motion. Although many of the biochemical mechanisms underlying the excitation-contraction coupling are not yet defined, it is known that cytosolic Ca2+ is the essential component in the coupling phenomenon. Inflammation of the human intestine causes increased levels of smooth muscle-specific actin, which in turn promotes the thickening of the smooth muscle layers. The increased smooth muscle actin may affect force production and further demonstrates the plasticity of smooth muscle cells in the inflamed intestine. Studies also show that human intestinal smooth muscle cells (HISMC) respond to IL-1beta and TNF-alpha stimulation by releasing IL-6, which may significantly contribute to the overall systemic inflammatory response. The availability of HISMC makes it more feasible to study the contractile and proliferative tissue responses of human intestinal smooth muscle. HISMC from ScienCell Research Laboratories are isolated from human intestine. HISMC are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HISMC are characterized by immunofluorescence with antibodies specific to α-smooth muscle actin. HISMC are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HISMC are guaranteed to further expand for 15 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Smooth Muscle Cell Medium (SMCM, Cat. #1101) for culturing HISMC in vitro.