Light Scattering Changes of Edetic Acid-Treated, Washed Rat Platelets

Summary

The effects of adenosine diphosphate (ADP) and Ca²⁺ on platelet morphology were studied in edetic acid (EDTA)-treated, washed platelets of rat by means of light scattering measurement at right angles. ADP caused a transient change of light scattering, which was independent of concentration above 5 μM and of pH between 4 and 10. When the platelets were pretreated with ADP or chilled persistently, Ca²⁺ also caused another transient change of light scattering. The effect of Ca²⁺ was abolished at pH below 6.5. The velocity of both ADP- and Ca²⁺-induced response was dependent on temperature, and the magnitude was reduced by metabolic inhibitors and SH-blocking agents. Adenosine triphosphate (ATP) competitively inhibited the ADP-induced response, but not the Ca²⁺-induced one. The response to Ca²⁺ of the control and chilled platelets was compared by scanning electron microgram. Apparent similarity of the effect of chilling on membrane structure to that of ADP was suggested.

• References

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