Bone marrow stromal cells are load responsive in vitro

Mechanical load-related effects on bone marrow stromal cells in vitro have been investigated. A dose response of a cyclical load of 1 Hz between 350 ustrain and 2500 ustrain applied to 10-day-old cultures resulted in elevated alkaline phosphatase levels and the number of cells expressing this protein after 2 days. No significant changes in the number of cells expressing or the production of collagen type 1 was observed. A critical stage of development of the cultures must be reached before load-related elevation in alkaline phosphatase expression could be measured independent of the stage at which loading was applied. Using a prostaglandin inhibitor at concentrations previously used in vivo, the load response was abolished. We have demonstrated that bone marrow stromal cells are load responsive in culture and have made preliminary studies into determining the involvement of prostaglandins in this process.