Percutaneous microembolization of the left coronary artery to model ischemic heart disease in rats.

Small animal models of myocardial infarction are used for a wide variety of research purposes, but common techniques for generating such models require thoracic surgeries that increase mortality risk and damage important structures, such as the pericardial sac. Here, we describe a technique for modeling myocardial infarction in rats by selective coronary microembolization, which has hitherto been described only in large animals. This technique selectively catheterizes the left coronary artery using a custom-made catheter that is introduced and precisely placed under fluoroscopic guidance.

Both ADP and thrombin regulate arteriolar thrombus stabilization and embolization, but are not involved in initial hemostasis as induced by micropuncture.

Objective: Thrombosis and embolization are main causes of morbidity and mortality. Up to now, the relative importance of mediators involved is only partly known. It was the aim of this study to investigate the involvement of ADP and thrombin in subsequent phases of arteriolar hemostasis and thromboembolism in vivo.

In vivo visualization of vascular leakage in photochemically induced cortical infarction.

The photothrombotic model for stroke was originally described as a focal cortical infarction resulting from occlusive thrombosis. However, subsequent studies have shown evidence for extravasation of water and proteins using ex vivo techniques. The aim of the present study was to determine the role of vascular leakage in the pathophysiology of photochemically induced infarction in vivo.

Tumor angiogenesis modulates leukocyte-vessel wall interactions in vivo by reducing endothelial adhesion molecule expression.

The expression of endothelial cell (EC) adhesion molecules involved in leukocyte-vessel wall interactions is suppressed in malignancies. In the present study, we investigated in vivo the regulation of leukocyte-vessel wall interactions by the presence of a tumor. By means of intravital microscopy, tumor necrosis factor alpha-stimulated leukocyte-vessel wall interactions were studied in ear skin microvessels of nude mice bearing small human LS174T colon carcinomas and in C57Bl/6 mice bearing murine B16F10 melanomas.

In vivo blockade of platelet ADP receptor P2Y12 reduces embolus and thrombus formation but not thrombus stability.

Objective: ADP is a key platelet agonist in thromboembolism. One of the receptors involved in ADP-induced platelet activation is the P2Y12 receptor, which is a target for antithrombotic drugs.

Methods And Results: Here, we present first evidence for a differential role of this receptor in thrombus and embolus formation in vivo.

Real-time detection of activation patterns in individual platelets during thromboembolism in vivo: differences between thrombus growth and embolus formation.

Knowledge on single platelet behavior and intracellular mechanisms during thromboembolism in vivo is scarce. In the present study, we used a new method that enables real-time detection and quantification of activation of individual platelets participating in a thromboembolic process in vivo, using their intracellular free Ca(2+) concentration ([Ca(2+)](i)) as a marker of activation. Isolated platelets were labeled with the Ca(2+)-sensitive fluorescent probe fluo-3 and injected into anesthetized rabbits so that 0.