MECHANICAL AND CHEMICAL PROPERTIES OF ARTERIES IN EXPERIMENTAL HYPERTENSION*

Abstract

Attention has been focused on the end organ of almost all forms of hypertension, the artery. An attempt has been made to quantitate some of the changes that the artery undergoes with hypertension. The chemical and mechanical properties of femoral arteries in hypertensive dogs were studied twice: once before hypertension, and again during experimental hypertension produced by wrapping the kidneys with cellophane. The elastic stiffness of the femoral artery was measured in vivo, and this pressure-radius relationship showed a significant increase with the development of hypertension. Evidence is presented to show that the increase in elastic stiffness was not due to the arterial walls" being stretched to a stiffer range because of elastic nonlinearity. The change in stiffness is probably a measurement of the change in the arterial-wall material during hypertension. The chloride, potassium, sodium, and water contents of the same vessels were determined before and during hypertension. The water content was found to increase with increasing elastic stiffness in hypertension. The interrelationships between the elastic modulus and the chemical composition of the arterial wall are briefly considered, but no simple relation seems apparent.