Signal Transduction During Platelet Plug Formation

New Fundamentals in Hemostasis

“…Once ligand-bound, these receptors regulate various heterotrimeric G proteins, the activities of which depend on whether the G protein ␣-subunits have bound GTP instead of GDP. Regulator of G protein signaling (RGS) proteins help to hydrolyze GTP, and thereby shorten the time period of G protein activation and thus of signaling (35). Various prominent GPCR on platelets signal to inhibit cAMP formation via adenylate cyclase, i.e., the adrenergic ␣ 2A -receptor for epinephrine (coupled to G z , also to G i ), the EP3 receptor for PGE 2 (coupled to G i ), and the P2Y 12 receptor for ADP (also coupled to G i ) (211).…”

Enhancement of Endothelial Function Inhibits Left Atrial Thrombi Development in an Animal Model of Spontaneous Left Atrial Thrombosis

“…In contrast, fresh thrombi, which are still in the development and expansion stage, consist mainly of blood material and are not yet organized by collagen. 28 These fresh thrombi are more elastic and have a lower stiffness, therefore, we immediately cut the hearts in half and rinsed them well with saline to removing residual blood before fixation. In the vasculature, endothelial dysfunction is also known to play an important role in thrombus development, including by decreasing blood flow and hypercoagulability, as shown in the wellknown Virchow's triad.…”

Differentiation Between Fresh and Old Left Ventricular Thrombi by Deformation Imaging

“…4,12,29 Thus, the intrinsic properties of the thrombus change with aging: the older thrombus is more fixed to the LV wall and less fragile because of its collagen-rich organization. 30 Although echocardiography plays a major role in the detection of LV thrombus after myocardial infarction, it is not possible to differentiate reliably between fresh and old intracavitary thrombi by standard echocardiography. Some criteria for age determination of LV thrombi by echocardiographic appearance have been suggested: reports state that fresh thrombi are highly mobile and tend to protrude to the LV cavity.…”

“…Fresh thrombi, which are still in the development and expansion stage, consist mainly of blood material and are not yet organized by collagen. 30 Thus, these fresh thrombi are more elastic, which leads to a higher degree of passive deformation during changes in cavitary pressure (assessed by deformation imaging) and a lower stiffness. In contrast, old thrombi are highly organized mostly by collagen, which results in a very rigid structure in this perpetuation stage. )…”