Endothelium and arteriosclerosis.

Endothelium, platelets and macrophages can each provide growth factors that may participate in atherosclerotic lesion initiation or progression, or both. These mitogens, coupled with alternations in endothelial integrity or function resulting from a variety of different risk-associated factors, such as hyperlipidaemia, hypertension, tobacco smoke, antibodies, infections, or homocystinaemia, may provide the basis for the intimal proliferative smooth muscle cell response of atherosclerosis. Platelets, endothelium or macrophages may be important in lesion initiation and progression in some circumstances but not in others, depending upon the extent and type of endothelial "injury'.