Thromb Haemost 1991; 66(03): 334-342
DOI: 10.1055/s-0038-1646417
Review Article
Schattauer GmbH Stuttgart

Rapid Aequorin Loading into Platelets in the Presence of DMSO - Characteristics of the Responses (Changes in Light Transmission and in Calcium) to Various Agonists

F Potevin
The Central Laboratory of Hematology, Hôtel-Dieu Hospital, Paris, France
,
T Lecompte
The Central Laboratory of Hematology, Hôtel-Dieu Hospital, Paris, France
,
R Favier
The Central Laboratory of Hematology, Hôtel-Dieu Hospital, Paris, France
,
M Samama
The Central Laboratory of Hematology, Hôtel-Dieu Hospital, Paris, France
› Author Affiliations
Further Information

Publication History

Received 20 July 1990

Accepted 04 March 1991

Publication Date:
25 July 2018 (online)

Summary

We have looked at different parameters which could modify platelet behaviour during and after aequorin loading in the presence of DMSO. There is a decreased platelet reactivity in response to ADP, PAF and A-23,187 which appears to be mainly due to the exposure to EGTA during washing and loading and the 1 ml volume of the test suspension. All the studied agonists (including PMA) which elicit aggregation are able to induce an intracellular Ca2+ change detected with the aequorin probe. By contrast, epinephrine alone induces neither aggregation nor Ca2+ rise, but potentiates the responses to ADP. Different consecutive phases in Ca2+ changes after stimulation with ADP, PMA and A-23,187 can be evidenced. In the presence of external Ca2+, the second component of the Ca2+ change evoked with ADP is dependent on aggregation and the subsequent TXA2 synthesis. When the external medium is Ca2+ depleted, the two Ca2+ peaks induced by ADP disappear whereas a Ca2+ rise persists (endogenous mobilization) with the other agonists, being independent of TXA2 and ADP release. Ca2+ mobilization parallels activation with A-23,187 but not with low concentrations of thrombin.