Hyperlipemia, fibrinolysis and arteriosclerosis

Area of Science:

• Biochemistry
• Cardiovascular Physiology
• Hematology

Background:

• Hyperlipemia is a risk factor for cardiovascular disease.
• The fibrinolytic system plays a crucial role in preventing thrombosis.
• The impact of hyperlipemia and vascular lesions on fibrinolysis requires further investigation.

Purpose of the Study:

• To investigate the influence of hyperlipemia on the fibrinolytic system in rats.
• To determine if vascular lesions modify the response of plasminogen activators to hyperlipemia.

Main Methods:

• Rats were administered three diets: two inducing hyperlipemia, and one inducing hyperlipemia with aortic lipid infiltration (arteriosclerosis).
• Fibrinolytic activity was assessed in plasma, aortic endothelial surface, and aortic wall.
• Plasminogen activator (PA) activity and fibrinolysis inhibitor activity were measured.

Main Results:

• Plasma PA activity increased in both hyperlipemic and arteriosclerotic groups compared to controls.
• Fibrinolysis inhibitor activity also increased in plasma.
• Fibrinolytic activity increased on the aortic endothelial surface and in the aortic wall in hyperlipemic groups; only the endothelial surface showed a significant increase in the arteriosclerotic group.
• A positive correlation was found between PA activity and hyperlipemia levels.
• No correlation was observed between aortic fibrinolytic activity and aortic cholesterol or triglyceride levels.

Conclusions:

• Hyperlipemia influences the fibrinolytic system, increasing plasma PA activity and aortic fibrinolytic activity.
• Arteriosclerosis may alter the response of the fibrinolytic system, with a notable increase in endothelial fibrinolytic activity.
• The findings highlight a complex interplay between lipid metabolism, vascular integrity, and fibrinolysis.