Lipid alterations

Mercury is known to exert an effect on the synthesis of membrane lipids. Mercuric chloride produces lipid alteration in pig kidney epithelial cells (LLC-PK, cells), with rapid accumulation of unesterified fatty acids (particularly arachidonic acid) and lysophospholipids and loss of cellular phospholipids... 

In isolated mouse nerves, the synthesis of all lipids is reduced after mercuric chloride, but the cholesterol synthesis is inhibited most strongly [ 123], It has been suggested that these lipid alterations might participate in the pathogenesis of membrane damage and cell death. 

An important question arises about the effects of phospholipid composition and the function of membrane-bound enzymes. The phospholipid composition and cholesterol content in cell membranes of cultured cells can be modified, either by supplementing the medium with specific lipids or by incubation with different types of liposomes. Direct effects of phospholipid structure have been observed on the activity of the Ca2+-ATPase (due to changes in the phosphorylation and nucleotide binding domains) [37]. Evidence of a relationship between lipid structure and membrane functions also comes from studies with the insulin receptor [38]. Lipid alteration had no influence on insulin binding, but modified the kinetics of receptor autophosphorylation. 

The role of the antioxidant properties of vitamins C, E, and p-carotene in the prevention of cardiovascular disease has been the focus of several recent studies. Antioxidants reduce the oxidation of low-density lipoproteins, which may play a role in the prevention of atherosclerosis. However, an inverse relationship between the intake or plasma levels of these vitamins and the incidence of coronary heart disease has been found in only a few epidemiological studies. One study showed that antioxidants lowered the level of high-density lipoprotein 2 and interfered with the effects of lipid-altering therapies given at the same time. While many groups recommend a varied diet rich in fruits and vegetables for the prevention of coronary artery disease, empirical data do not exist to recommend antioxidant supplementation for the prevention of coronary disease. 

Lynch, D.V. Steponkus, P.L. (1987). Plasma membrane lipid alterations associated with cold acclimation of winter rye seedlings (Secale cereale L. cv. Puma). Plant Physiology 83, 761-7. 

Cohen CJ. Ritonavir-boosted protease inhibitors, part 2 cardiac implications of lipid alterations. AIDS Read. 2005 15 528-532, 537-538. 

C23. Cramp, D. G, Plasma lipid alterations in patients with chronic renal disease. CRC Clin. Lab. Sci. 17, 77-101 (1982). 

Bums, C. P., and Dudley, D. T., 1982, Temperature dependence and effect of membrane lipid alteration on melphalan transport in LI 210 murine leukemia cells, Biochem. Pharmacol. 31 2116-2119. 

Baycol was indicated as an adjunct to diet to reduce elevated total-cholesterol, low-density lipoprotein cholesterol (LDL-C), apo B, and triglycerides (TG) and to increase high-density lipoprotein cholesterol (HDL-C) levels in patients with primary hypercholesterolemia and mixed dyslipidemia (Fredrickson types Ila and Ilb) when the response to dietary restriction of saturated fat and cholesterol and other nonpharmacological measures alone had been inadequate. Therapy with lipid altering drugs should bea component of multiple risk factor intervention in those patients at significantly high risk for atherosclerotic vascular disease due to hypercholesterolemia. 

Bohn M., Liithje S., Sperling P., Heinz E., Dorffling K. Plasma membrane lipid alterations induced by cold acclimation and abscisic acid treatment of winter wheat seedlings differing in frost resistance. Journal of Plant Physiology 2007 164(2) 146-156. 

Hepatocellutar Disease. Most forms of acute or chronic hepatocellular disease, including acute viral hepatitis and cirrhosis with jaundice, are associated with decreased levels of Hp, possibly caused in part by altered estrogen metabolism. Increased red cell breakdown secondary to erythrocyte membrane lipid alterations may also play a role, although this has never been documented with turnover studies. In contrast, biliary obstruction is also associated with significant lipid alterations but with increased Hp levels, in the absence of severe hepatocellular disease. 

Manninen V, Elo MO, Frick MH, Haapa K, Heinonen OP, Heinsahni P, et al. Lipid alterations and decline in... 

Some combinations of lipid-altering drugs are currently available such as extended-release niacin/lovastatin and ezetimibe/simvastatin, which are more promising for lipid-lowering therapy with stronger effects and decreased adverse reactions. 

Galli C, White H, Paoletti R. Lipid alterations and their reversion in the central nervous system of growing rats deficient in eesential fatty acids. Lipids 1971 6 378-387. 

Chronic effects on epileptogenesis Membrane lipid alterations Synaptic reorganization Metabolic adaptations... 

When similar lipid abnormalities are present in other family members in a pattern of autosomal dominant inheritance and no secondary causes for these lipid alterations (e.g., hypothyroidism) are present, the entity referred to as familial hypercholesterolemia (FH), type llA is the most likely cause of this hereditary dys-lipidemia. 

Okamoto, H., Kawaguchi, H., Minami, M., Saito, H., and Yasuda, H. (1989) Lipid Alterations in Renal Membrane of Stroke-Prone Spontaneously H3fpertensive Rats, Hypertension 13, 456-462. 

Maki, K.C et al. Lipid-altering effects of different formulations of hydroxypropylmethylcellulose. J. Clin. Lipidol. 2009, 3(3), 159-166. 

M. H. Davidson, Overview of prevention and treatment of atherosclerosis with lipid-altering therapy for pharmacy directors. Am. J. Manag. Care 13 (2007) S260-S269. 

---