Triglycerides activated

It starts however on the cytosolic side With fatty acids coming from triglyceride Activated in the thiokinase way To thioester of CoA. 

RandomiZation/Interesterification. Transesterification occurs when a carboxyUc acid (acidolysis) or alcohol (alcoholysis) reacts with an ester to produce a different ester (20). Ester—ester interchange is also a form of transesterification. If completely unsaturated triglyceride oil (UUU) reacts with a totally saturated fat (SSS) in the presence of an active catalyst such as sodium, potassium, or sodium alkoxide, triglycerides of intermediate composition may be formed. 

Phospholipids. Phospholipids, components of every cell membrane, are active determinants of membrane permeabiUty. They are sources of energy, components of certain enzyme systems, and involved in Hpid transport in plasma. Because of their polar nature, phosphoUpids can act as emulsifying agents (42). The stmcture of most phosphoUpids resembles that of triglycerides except that one fatty acid radical has been replaced by a radical derived from phosphoric acid and a nitrogen base, eg, choline or serine. 

Potentiometry is another useful method for determining enzyme activity in cases where the reaction Hberates or consumes protons. This is the so-called pH-stat method. pH is kept constant by countertitration, and the amount of acid or base requited is measured. An example of the use of this method is the determination of Hpase activity. The enzyme hydroly2es triglycerides and the fatty acids formed are neutralized with NaOH. The rate of consumption of NaOH is a measure of the catalytic activity. 

In addition to having the required spedfidty, lipases employed as catalysts for modification of triglycerides must be stable and active under the reaction conditions used. Lipases are usually attached to supports (ie they are immobilised). Catalyst activity and stability depend, therefore, not only on the lipase, but also the support used for its immobilisation. Interesterification reactions are generally run at temperatures up to 70°C with low water availability. Fortunately many immobilised lipases are active and resistant to heat inactivation under conditions of low water availability, but they can be susceptible to inactivation by minor components in oils and fats. If possible, lipases resistant to this type of poisoning should be selected for commercial operations. 

PLTP is responsible for the majority of phospholipid transfer activity in human plasma. Specifically, it transfers surface phospholipids from VLDL to HDL upon lipolysis of triglycerides present in VLDL. The exact mechanism by which PLTP exerts its activity is yet unknown. The best indications for an important role in lipid metabolism have been gained from knockout experiments in mice, which show severe reduction of plasma levels of HDL-C and apoA-I. This is most likely the result of increased catabolism of HDL particles that are small in size as a result of phospholipid depletion. In addition to the maintenance of normal plasma HDL-C and apoA-I concentration, PLTP is also involved in a process called HDL conversion. Shortly summarized, this cascade of processes leads to fusion of HDL... 

The steps in the subsequent utilization of muscle LCFAs may be summarized as follows. The free fatty acids, liberated from triglycerides by a neutral triglyceride lipase, are activated to form acyl CoAs by the mediation of LCFAcyl-CoA synthetase which is situated on the outer mitochondrial membrane. The next step involves carnitine palmitoyl transferase I (CPT I, see Figure 9) which is also located on the outer mitochondrial membrane and catalyzes the transfer of LCFAcyl residues from CoA to carnitine (y-trimethyl-amino-P-hydroxybutyrate). LCFAcyl... 

Activities of glutamate-pyruvate transaminase (SGPT, GPT) (EC 2.6.1.2), L-y -glutamyl-transferase (y-GT) (EC 2.3.2.2) and level of triglycerides (TG) in serum, as well as levels of glutathione (GSH) and malondialdehyde (MDA) in the liver were determined. 

Triglycerides of 150 mg/dL (1.70 mmol/L) or greater or active treatment to lower triglycerides. 

Resins are moderately effective in lowering LDL cholesterol but do not lower triglycerides (Table 9-8). Moreover, in patients with elevated triglycerides, the use of a resin may worsen the condition. This may be due to a compensatory increase in HMG-CoA reductase activity and results in an increase in assembly and secretion of VLDL. The increase in HMG-CoA reductase activity can be blocked with a statin, resulting in enhanced reductions in serum lipids (see section on combination therapy). Resins reduce LDL cholesterol from 15% to 30%, with a modest increase in HDL cholesterol (3% to 5%) (Table 9-8). Resins are most often used as adjuncts to statins in patients who require additional lowering of LDL cholesterol. Since these drugs are not absorbed, adverse effects are limited to the gastrointestinal tract (Table 9-9). About 20%... 

Fibrates work by reducing apolipoproteins B, C-III (an inhibitor of LPL), and E, and increasing apolipoproteins A-I and A-II through activation of peroxisome proliferator-activated receptors-alpha (PPAR-a), a nuclear receptor involved in cellular function. The changes in these apolipoproteins result in a reduction in triglyceride-rich lipoproteins (VLDL and IDL) and an increase in HDL. 

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