The invention is directed to methods of modulating ischemic injury in tissues and organs. The invention is further directed to methods of increasing time to ischemic injury in tissues and organs. Such methods utilize compositions comprising cells capable of modulating inflammatory responses, referred to herein as Inflammatory Response Modulating Cells (IRMCs). The IRMCs any be used directly or cell membranes derived from them may be used in practicing the methods of the invention. In addition, the IRMCs and IRMC membranes may be used alone or in combination with each other and/or in combination with various suitable active agents.