Factors regulating plasma cholesterol concentration.

Abstract

Plasma cholesterol concentration in humans and animals is held at remarkably constant level under constant dietary condition. Critical reevaluation of our studies indicated that cholesterol absorption and fecal excretion rather than cholesterol synthesis play major role in regulating plasma cholesterol concentration in high- and low-responding rhesus monkeys. The high-responding monkeys are those who respond with mild increase in plasma cholesterol when fed high cholesterol diet while the low-responding monkeys are those who respond with mild increase in plasma cholesterol when fed an identical high cholesterol diet. Humans also respond differently when fed high cholesterol diet, i.e., there are high- and low-responding humans. I suggest that in humans also cholesterol absorption and fecal excretion rather than cholesterol synthesis play greater roles in the regulation of plasma cholesterol concentration.