Age-Related Contractile Force of Human Vessels

The following study was performed to investigate whether age-related differences in contractile force between veins and arteries exist. Data were taken from experiments of various in vitro projects performed by the same persons. Macroscopically unchanged human vessels were obtained from bypass surgery and from surgical removal of varicose veins. Parameters for contractile responses to 5-hydroxytryptamine, noradrenaline, U46619 and potassium chloride were calculated on vascular ring preparations in organ bath studies. The contractile force of human saphenous veins was generally stronger than that of internal thoracic arteries, but there was an agedependent decrease in contractile force of human veins while contractile responses of internal thoracic arteries remained fairly constant. In conclusion, the contractile force of the smooth muscle of human saphenous veins was generally higher than that of internal thoracic arteries but it declined with age while that of the arteries remained unchanged. This finding might contribute to elucidate the patency of saphenous veins when used as coronary artery bypass. In addition it might help to explain the pathophysiology of chronic orthostatic hypotension which is a common problem among elderly patients.