Effect of diclofenac-sodium (Voltaren) on the electrical charge of human platelet membrane.

Platelets incubated with prostaglandin synthetase inhibitors, i.e. aspirin (ASA) and diclofenac-sodium (Voltaren) show a decreased capability to aggregate. While ASA induces the complete loss of platelet pseudopodia, Voltaren causes the appearance of long, needle-shaped pseudopodia, a finding which may suggest a rather increased tendency to aggregate. Platelets labeled with ferritin hydrazide and examined with a transmission electron microscope and by X-ray analysis show a greater deposition of ferritin hydrazide after incubation with Voltaren in comparison to those incubated with ASA and to the controls. This finding suggests an increased negative charge of the stretched platelet membrane after incubation with Voltaren with a subsequent increase in the repulsive forces between platelets.