Fig. 2.

Compartmental model for metabolism of preβ-1 and α-HDL in African Green Monkeys. Compartment 1: plasma preβ-1 apoA-I. Compartment 11: noncirculating preβ-1 apoA-I. Compartment 2: plasma α-3 apoA-I. Compartment 21: Noncirculating α-3 apoA-I. Compartment 3: plasma α-2 apoA-I. Compartment 4: plasma α-1 apoA-I. Compartments 5 and 6: delay compartments. Selectively delipidated vervet plasma containing preβ-1-like, α-3, α-2, and α-1 HDL was infused into five recipient vervets. Noncirculating compartments 11 and 21 are required for preβ-1 and α-3 HDL because the amount of injected donor apoA-I in these two fractions was significantly higher than the increment in plasma preβ-1 and α-3 HDL observed in recipient monkeys (i.e., only a fraction of injected apoA-I appears in plasma immediately after infusion and the rest appears after a delay). The residence times for the noncirculating compartments of preβ-1 and α-3 HDL are the reciprocals of the rate constants k(1,11) and k(2,21), respectively. Data represented are mean ± SEM from modeling five monkeys individually. k, rate constants (pools/day); d, delay compartment; % = flux distributions.