Prechylomicron Transport Vesicle Research Articles

Pre-chylomicron transport vesicles (PCTV) utilize the vesicle associated membrane protein 1 (VAMP 1) and synaptosomal associated protein 25 (SNAP 25) dependent pathway

Pre-chylomicron transport vesicles (PCTV) utilize the vesicle associated membrane protein 1 (VAMP 1) and synaptosomal associated protein 25 (SNAP 25) dependent pathway

Nutrient absorption

Some key advances occurred last year in understanding mechanisms involved in nutrient absorption. A novel "prechylomicron transport vesicle" was identified; its movement to the Golgi is the rate-limiting step for triacylglycerol absorption. A scavenger receptor (type BI) in the brush border membrane appears to facilitate cholesterol uptake. Several studies define mechanisms for gastrointestinal peptide hormone stimulation of glucose uptake. An oligopeptide transporter, PepT1, is transcriptionally upregulated by certain dietary amino acids and dipeptides. Surprisingly, both insulin and fasting double the maximum velocity for dipeptide uptake (via PepT1), but they act by different mechanisms. Three transporters, SMVT (sodium-dependent multivitamin transporter for biotin and pantothenate), SVCT (for vitamin C), and CaT1 (for Ca uptake from the lumen) have been cloned and are active when expressed in various cells. Additional studies provide insights on Ca absorption and vitamin D action in aging, estrogen deficiency, and adaptation to a low Ca diet. Nramp2, also called DMT1 (divalent metal ion transporter), seems to be a major regulator of transferrin-independent, nonheme iron uptake. Finally, the protein HFE associates with the transferrin receptor and is part of an iron-sensing mechanism that regulates iron absorption. It is defective in hereditary hemochromatosis. HFE and Nramp2 (DMT1) genes are reciprocally regulated.

Prechylomicron transport vesicle: isolation and partial characterization.

The intestine is able to regulate its output rate of chylomicrons, the major intestinal triacylglycerol (TG) transport vehicle. We have proposed that a vesicle, transporting the developing chylomicron from the endoplasmic reticulum (ER) to the Golgi, is the rate-limiting step in the process of TG transit through the enterocyte [Am. J. Physiol. 273 (Gastrointest. Liver Physiol. 36): G18-G30, 1997]. We wished to isolate and characterize this vesicle. The apical portion of rat intestinal cells were avulsed, and the mucosa was stirred in buffer. The supernatant was centrifuged in two different sucrose gradients, and the top 2.5 ml of the last gradient were collected and concentrated. Electron microscopy showed a 200-nm vesicle. The vesicle contained immunoidentifiable apolipoprotein (apo) B48 and apo A-IV but very little apo A-I, although apo A-I was present in the ER and Golgi. [3H]TG-loaded vesicles delivered [3H]TG to the Golgi but not the ER. Marker enzyme assays also indicate that the isolated fraction is different from the ER and Golgi fractions. We conclude that we have isolated a vesicle that is post-ER but pre-Golgi that vectorially transports TG to the Golgi.

Particulate fat in lymph and blood.

ArticlesParticulate Fat in Lymph and BloodVincent P. Dole, and James T. Hamlin IIIVincent P. Dole, and James T. Hamlin IIIPublished Online:01 Oct 1962https://doi.org/10.1152/physrev.1962.42.4.674MoreSectionsPDF (4 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Download PDF FiguresReferencesRelatedInformation Cited ByNeuronal Lipid Metabolism: Multiple Pathways Driving Functional Outcomes in Health and Disease23 January 2018 | Frontiers in Molecular Neuroscience, Vol. 11Liver Fatty Acid-binding Protein Initiates Budding of Pre-chylomicron Transport Vesicles from Intestinal Endoplasmic ReticulumJournal of Biological Chemistry, Vol. 282, No. 25Hydrophobic nature of rat lymph chylomicronsClinica Chimica Acta, Vol. 342, No. 1-2Difference in effect of myristic and stearic acid on plasma HDL cholesterol within 24 h in young men5 June 2003 | European Journal of Clinical Nutrition, Vol. 57, No. 6Fibrinogen-coated chylomicrons in gastrointestinal lymph: a new rationale regarding the arterial deposition of postprandial lipidsMedical Hypotheses, Vol. 59, No. 6Effect of 6 dietary fatty acids on the postprandial lipid profile, plasma fatty acids, lipoprotein lipase, and cholesterol ester transfer activities in healthy young menThe American Journal of Clinical Nutrition, Vol. 73, No. 2Bezafibrate therapy in patients with isolated low high-density lipoprotein cholesterol levels may have a beneficial effect in prevention of atherosclerosisMetabolism, Vol. 44, No. 11Impaired triacylglycerol catabolism in hypertriglyceridemia of the diabetic, cholesterol-fed rabbit: a possible mechanism for protection from atherosclerosisBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 1002, No. 3Reduced atherogenesis in cholesterol-fed diabetic rabbits. Giant lipoproteins do not enter the arterial wall.Arteriosclerosis: An Official Journal of the American Heart Association, Inc., Vol. 8, No. 4Effects of lipid composition on the association of plasma proteins with lipid emulsionsJournal of Colloid and Interface Science, Vol. 113, No. 2Zonal ultracentrifugationThe phase behavior of triolein, cholesterol, and lecithin emulsionsJournal of Colloid and Interface Science, Vol. 89, No. 2Effect of size and competition by lipoproteins and apolepoproteins on the uptake of chylomicrons and chylomicron remnants by hepatoma cells in cultureBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 617, No. 2Altered apolipoproteins in sex steroid-treated ratsMetabolism, Vol. 27, No. 5Effects of adrenaline on blood sugar and plasma lipid levels of a hibernating lizard during active and hibernation periodComparative Biochemistry and Physiology Part C: Comparative Pharmacology, Vol. 60, No. 2Alterations in levels and interrelations of plasma apolipoproteins induced by dietMetabolism, Vol. 25, No. 3Apoliporoteins in human pregnancyMetabolism, Vol. 24, No. 8The apoproteins of various size classes of human chylous fluid lipoproteinsBiochimica et Biophysica Acta (BBA) - Protein Structure, Vol. 371, No. 1Release of phagocytosed cholesterol by liver macrophages and spleen cellsBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 260, No. 3A connective tissue membrane as a molecular sieveBiochimica et Biophysica Acta (BBA) - Biomembranes, Vol. 255, No. 1Studies on the equilibration of radioisotopic cholesterol with human serum lipoprotein cholesterol in vitroBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 152, No. 4Relation between dietary fat and fatty acid composition of “endogenous” and “exogenous” very low density lipoprotein triglycerides (D < 1.006)Metabolism, Vol. 17, No. 6Separation and quantitative analysis of serum lipoproteins by means of electrophoresis on cellulose acetateClinica Chimica Acta, Vol. 20, No. 2Diet, cholesterol metabolism, and atherosclerosis1 November 1967 | Journal of the American Oil Chemists' Society, Vol. 44, No. 11Chylomicron, free fatty acid and ketone body metabolism of isolated liver cells and liver homogenatesBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 137, No. 1L'activité lipolytique du tissu adipeux i. mesures potentiométriques dans un extrait brut de tissu adipeux de ratBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 137, No. 1Hepatic lipase in the ratBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 137, No. 1The role of the liver in the uptake of plasma and chyle triglycerides in the ratBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 125, No. 3A new technique for the investigation of the low-density lipoproteins in health and diseaseClinica Chimica Acta, Vol. 14, No. 6The effect of diet and thyroxin on plasma lipids in myxedemaMetabolism, Vol. 15, No. 2Metabolism in the rat of chyle obtained after feeding hydrogenated coconut oil labeled with stearic acidBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, Vol. 106, No. 1EditorialCirculation, Vol. 31, No. 3Unilateral chylous lymphedema and xanthomatosisThe American Journal of Medicine, Vol. 37, No. 4Heparin and the removal of triglyceride from the blood streamThe American Journal of Cardiology, Vol. 14, No. 1Über die resorption und den stoffwechsel einiger I-14C-markierter freier fettsäuren bei jungen kaninchenClinica Chimica Acta, Vol. 9, No. 2 More from this issue > Volume 42Issue 4October 1962Pages 674-701 https://doi.org/10.1152/physrev.1962.42.4.674PubMed14028424History Published online 1 October 1962 Published in print 1 October 1962 Metrics