EVIDENCE THAT ELECTRICAL AND MECHANICAL STIMULATION CAN INDUCE REPTILASE-CLOT RETRACTION

A marked clot retraction was always observed in the clots [human] stimulated for more than 4 min. PPP [platelet poor plasma] did not retract after a similar stimulation, confirming that the electrical stimulation activated platelets. The retraction, following the electrical stimulation, was not immediate but retained characteristics of a slowly evolving process; the stimulation may be only a trigger for the retraction. When reptilase-PRP [platelet rich plasma]-clots were stimulated mechanically, the result was constantly a marked clot retraction. In contrast, PPP-clots, which underwent the same mechanical stimulation, did not retract. The electrical stimulation of the platelets within the clot apparently induced some modifications of the permeability of the platelet membrane(s) with following availability of intracellular Ca ions which in turn control the contractile activity of platelets.