Methods of medical treatment and diagnosis using mediators released by endothelial cells stimulated by external addition of pulses to the circulation are disclosed. The external pulses produce circumferential shear stress in body fluid channels that subsequently stimulates the endothelial cells to produce mediators that become available for therapeutic and diagnostic purposes. The preferred means of adding external pulses is the mechanical inducement of periodic acceleration of the body or parts of the body by a reciprocating motion platform.