Blood - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 9

BLOOD

GUT LIVER

biliary acids

Cs

chylomicron

Cs

VLDL

Apo

LPLase

LDL

CETP

TISSUES

Apo

HDL

Apo

Cs

Cs

Fig. 1.2 Cholesterol turnover

liver that are packaged into VLDLs and released into the circulation. VLDL particles
(size 30-80 nm) contain also cholesteryl esters and apolipoproteins (ApoB100,
ApoC1-ApoC3, and ApoE).
Intermediate-density lipoproteins (IDL) are formed from VLDLs by lipoprotein
lipase after triacylglycerol removal. 11 IDL particles become LDLs (size 20 nm) after
losing the whole TG content. Plasma LDL contains cholesterol esters in its core and
a hydrophilic coat composed of cholesterol, phospholipids, and ApoB100.
Blood lipids require many types of molecules from their synthesis, exocytosis out
of producing cells, and blood transport, to cell capture (receptors) and endocytosis,
and degradation (Table 1.7 ).

11 IDL particles retain cholesteryl esters. Some IDLs are rapidly taken up by the liver, whereas
others remain in the blood and are converted to LDL particles.