chylomicrons are the four major types of plasma lipoproteins.
what are the four major types of plasma lipoproteins?
chylomicrons
due to the hydrophobic nature of membrane lipids, triglycerides and cholesterols, they require special transport proteins known as lipoproteins. the amphipathic structure of lipoproteins allows the tryglycerols and cholesterol to be transported through the blood. chylomicrons are one sub-group of lipoproteins which carry the digested lipids from small intestine to the rest of the body. the varying densities between the types of lipoproteins are characteristic to what type of fats they transport. for example, very-low-density lipoproteins (vldl) carry the synthesized triglycerides by our body and low-density lipoproteins (ldl) transport cholesterol to our peripheral tissues. a number of these lipoproteins are synthesized in the liver, but not all of them originate from this organ.
lipid metabolism
as disturbances in plasma lipid and lipoprotein transport are established risk factors for atherosclerotic diseases such as myocardial infarction and stroke the initial scientific activities of patsch focused on the characterization of human lipoproteins. using zonal ultracentrifugation methods developed by josef r. patsch (and in collaboration with him), a detailed physical and chemical description of very low-density and high-density lipoproteins was completed. the methods of lipoprotein isolation, developed in innsbruck, were used by patsch for many clinical studies at washington university in st. louis. in the laboratory of gustav schonfeld, patsch used rat liver perfusions and primary rat hepatocyte cultures to determine the effects of diets and hormones such as insulin and thyroid hormone on hepatic lipoprotein biosynthesis. these studies were continued at baylor college of medicine in houston in collaboration with w. strobl and s.m. soyal. in a collaborative effort with josef r. patsch and antonio m. gotto, the strong predictive value of the magnitude of postprandial lipemia for coronary heart disease was established. patsch was one of the principal investigators of the atherosclerosis risk in communities study (aric) from 1985-94. as atherosclerotic disease is often asymptomatic for many years, knowledge about the quantitative importance of risk factors is essential to effectively manage the disorder and reduce its life-threatening sequels. aric investigators ascertained the effect size of numerous established and candidate risk factors in well characterized populations using the intima-media thickness of the common carotid arteries as surrogate marker for atherosclerosis and cardiovascular endpoints as outcomes. patsch contributed to several research projects that quantified the risk associated with plasma lipoproteins including lipoprotein(a) in the fasting and postprandial state. after his return to austria, patsch concentrated on genetic and functional aspect of energy metabolism. a main research focus was pgc-1alpha, a transcriptional co-activator that orchestrates several biological programs including mitochondrial biogenesis. other genetic factors with relevance for obesity, type 2 diabetes and the metabolic syndrome also were studied in collaboration with h. esterbauer, h. oberkofler, t. felder and f. krempler. more recently, s.m. soyal and patsch discovered brain-specific isoforms of pgc-1alpha which are likely to play a role in neurodegenerative disorders such as huntington's disease, amyotrophic lateral sclerosis and parkinson's disease.
wolfgang patsch