Very lowdensity lipoprotein chylomicrons and triglyceride transport

Chylomicrons and VLDL particles each contain surface apolipoprotein-B (apoB). Chylomicrons are assembled primarily in the intestine and contain a smaller version, apoB-48, whereas VLDL particles contain the larger apoB-100 surface protein and are primarily assembled in the liver. The functional role for VLDL and chylomicron particles is to deliver TG to peripheral tissue. TG accounts for nearly half (48%) of the mass in VLDL particles analyzed from healthy human control groups (Table 2).10 VLDL particles have commensurately lower levels of FC and cholesteryl ester. Human TG plasma levels in healthy subjects are considered normal if they fall below 200mgdL_ 1.10 Plasma TG levels in hypertriglyceridemic subjects exceed 200mgdL_ 1 due to significantly increased plasma VLDL.

In the periphery, LpL acts on these particles to release the TG to adipose tissue for fat storage or to muscle tissue where they can be used for energy. The resulting TG-depleted and cholesteryl ester-enriched VLDL remnant particles can be recycled to the liver by the interaction of a specific hepatic LDL receptor (LDLr) with apoB and apolipoprotein-E (apoE). Alternatively, further remodeling of VLDL remnants produces cholesteryl ester-enriched particles: first IDL and then LDL. In contrast to VLDL and chylomicrons, the smaller and denser LDL and HDL particles help move cholesterol to and from the periphery, respectively.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

Get My Free Ebook


Post a comment