Defects in fibrin clot retraction and MLC phosphorylation in E2-treated mice. (A) Fibrin clot retraction assays were performed in PRP adjusted to 3 × 108 platelets/mL and treated with both thrombin (2 IU/mL) and atroxin (0.1 μg/mL). Photographs shown are representative of 4 independent experiments. (B) Impact of E2 treatment on MLC phosphorylation over time. Platelets from mice treated or not with E2 were stimulated by 0.3 IU/mL thrombin for the indicated time and probed by immunoblotting with an anti-phospho-MLC Ab (ser 19) or a total MLC Ab. Phosphorylation levels were estimated by densitometry analysis of Western blots, and the results are expressed as percentages of maximum phosphorylation (10 seconds stimulation of control mice) and are mean ± SEM of 4 independent experiments. Significant difference **P < .01, *P < .05, according to a Student t test.
