Effect of long-term aluminum feeding on lipid/phospholipid profiles of rat brain myelin
© Pandya et al; licensee BioMed Central Ltd. 2004
Received: 16 December 2003
Accepted: 22 June 2004
Published: 22 June 2004
Effect of long-term (90–100 days) exposure of rats to soluble salt of aluminum (AlCl3) on myelin lipid profile was examined. The long-term exposure to AlCl3 resulted in a 60 % decrease in the total phospholipid (TPL) content while the cholesterol (CHL) content increased by 55 %. Consequently the TPL / CHL molar ratio decreased significantly by 62 %. The phospholipid composition of the myelin membrane changed drastically; the proportion of practically all the phospholipid classes decreased by 32 to 60 % except for phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Of the latter two, proportion of PC was unchanged while PE increased in proportion by 47 %. Quantitatively, all phospholipid classes decreased by from 42 to 76% with no change in the PE content. However the membrane fluidity was not altered in Al-treated rats. Many of the changes we observe here show striking similarities with the reported phospholipid profiles of Alzheimer brains.
Loss of short-term memory marks the beginning of Alzheimer's disease (AD) and the condition ultimately leads to progressive dementia [1–7]. This involves memory loss, disorientation and impairment of judgement and reasoning [1–7]. Pathologically, abnormally high deposits of senile plaques comprising β-amyloid protein and, neurofibrillary tangles in specific brain regions have been reported [4, 8, 9]. In later stages of AD reduced levels of neurotransmitters and extensive neuronal and synaptic loss are the common biochemical features [2, 3, 6, 10–13]. Specifically, there is a selective loss of acetylcholine releasing neurones in the basal forebrain, hippocampus and cortex [12, 13]. Impaired cholinergic function in AD has been correlated with loss of memory [2, 6, 10, 12].
Amongst the various hypotheses concerning AD [2, 7, 14–16], the membrane hypothesis [7, 16] and the one implicating aluminum (Al) as a possible environmental etiologic factor [7, 15, 17–22] are of considerable interest. Neurotoxicity from exposure to Al is known to result in impairment of learning memory and cognition function both from clinical observations and from animal experiments [5, 14, 15, 17, 23]. Crapper et al. reported that the concentrations of Al in the brains of AD patients were significantly high . Long-term administration of soluble salt of Al to rats worsens their learning ability together with diminished cholinergic function and the rats become lethargic [14, 15, 17, 23]. Role of Al intoxication in neurodegenerative diseases has been recently emphasized [18, 24–29].
Earlier studies from our laboratories have shown that prolonged treatment with AlCl3 given in the diet caused significant impairment of energy metabolism in the rat brain mitochondria . In parallel studies, we also noted that this treatment resulted in decreased proportion and content of phospholipid classes in the rat brain microsomal and synaptic plasma membranes [30, 31]. Importance of myelin membrane for insulation is well documented . It was therefore of interest to find out if prolonged treatment with AlCl3 can affect the myelin lipid profile. The findings of these investigations are summarized in the present communication. The results of our present studies show that indeed the prolonged exposure to AlCl3 resulted in significant changes in content and composition of phospholipid classes and in cholesterol content of the rat brain myelin. It is possible that this altered lipid /phospholipid content and composition could affect the insulation properties of the myelin. The finding may thus have some bearing on loss of short-term memory in Alzheimer's disease.
Materials and Methods
Silica gel G was purchased from E. Merck, Germany and 1,6 diphenyl-1,3,5 hexatriene (DPH) was purchased from Sigma, U.S.A. All other chemicals were of analytical – reagent grade and were purchased locally.
Animals and treatment with Al
Adult male albino rats (100–120 g, 6–7 week old) of Charles-Foster strain were given in their diet 100 mg of AlCl3 /kg body weight /day for 90 to 100 days [19, 30, 33]. The animals were weighed every week and accordingly the dose of AlCl3 was adjusted on weekly basis. The animals in control group were given equivalent amounts of NaCl. The regimen for Al treatment is described in detail in . We have earlier shown that under these conditions, compared to controls, in the experimental group the Al body burden is about 2.2 times higher throughout the experimental period .
Isolation of myelin
At the end of the treatment period, the animals were killed by decapitation and their brains were quickly dissected out and kept in beakers containing chilled (0 to 4°C) 0.25 M sucrose. Isolation of myelin from 20 % (w/v) homogenates was according to the procedure of Burgyone and Rose , as described [30, 35], which is based on discontinuous sucrose density gradient centrifugation. Briefly, after the removal of nuclei and cell debris at 600 × g for 10 min., the combined mitochondrial-synaptosomal-myelin fraction was sedimented by centrifugation at 10,000 × g for 10 min. The resulting pellet was then subjected to hypotonic lysis using 5 ml of 5 mM Tris-HCl buffer pH 8.1. After incubation at 0°C for 30 min., the lysate was mixed with 5.0 ml of 80 % (w/w) sucrose, transferred to a to a centrifuge tube of a Beckman SW 28.1 rotor and was carefully over layered with 10.0 ml of 28.5% (w/w) sucrose, followed by 8.0 ml of 10% (w/w) sucrose. The tubes were then subjected to centrifugation at 60,000 × g for 1.5 hr. The myelin fraction banding at the top of the gradient was carefully removed, resuspended in 0.25 M sucrose and re-sedimented by centrifugation at 100,000 × g for 40 min. in a TFT80 rotor. The resulting pellets were suspended in 0.25 M sucrose to give a final protein concentrations of 2–3 mg / ml. All operations were carried out at 0–4°C.
The isolated myelin fraction showed only negligible Na+, K+_ ATPase activity .
Extraction of total lipids , and estimations of cholesterol and phospholipid phosphorus were by the procedures described [37, 38]. The phospholipid classes were separated by thin layer chromatography . The detailed procedures have been described earlier .
Membrane fluidity measurements
Measurements of membrane fluidity were carried out at 25°C in a Shimadzu RF 5000 spectrophotoflourimeter using 1,6 diphenyl-1,3,5 hexatriene (DPH) as the probe as described in details earlier .
Protein estimation was according to the method of Lowry et al.,.
Statistical evaluation of the data was by Student's 't'-test.
Effect of long-term Al feeding on the total phospholipid and cholesterol content of myelin membrane in the rat brain.
TPL (μg/mg protein)
CHL (μg/mg protein)
TPL/CHL (mole : mole)
1357.4 ± 136.4
785.1 ± 36.5
0.86 ± 0.07
824.7 ± 95.8*
1222.1 ± 104.9**
0.33 ± 0.04***
Effect of long-term Al feeding on phospholipid composition of myelin membrane in the rat brain.
Phospholipid composition (% of total)
5.85 ± 0.61
3.53 ± 0.28*
9.29 ± 0.52
6.31 ± 0.38**
27.63 ± 1.51
26.12 ± 0.78
6.18 ± 0.78
3.28 ± 0.29*
8.96 ± 0.83
3.58 ± 0.46**
37.48 ± 1.00
55.20 ± 1.58**
5.33 ± 0.38
2.20 ± 0.33**
Effect of long-term Al feeding on phospholipid content of individual phospholipids of myelin membrane from the rat brain.
Phospholipid content (μg / mg protein)
79.46 ± 8.18
28.74 ± 2.79*
125.86 ± 9.83
52.86 ± 4.69*
376.08 ± 28.18
216.56 ± 15.77*
84.36 ± 9.65
26.69 ± 2.72*
121.74 ± 10.89
29.61 ± 3.63*
506.86 ± 33.36
456.06 ± 33.18
71.39 ± 6.13
18.04 ± 2.41*
From the foregoing results it is clear that Al-treatment resulted in significant reduction in the phospholipid content accompanied by major compositional changes, which is consistent with membrane hypothesis of AD [2, 16]. According to this hypothesis, in order to make up for the choline deficiency, the neurons try to extract choline from choline containing phospholipids. This results in the disruption of cell membranes and ultimately in neuronal cell death . From the data presented (Tables 2 and 3), it is clear that this decrease occurred in both sphingomyelin (SPM) and PC with the effect being more pronounced on the former component. In related studies we have observed that in the synaptic plasma membranes also the content of SPM decreased significantly in Al-treated rats, while the effect on PC component was of lesser magnitude [30, 31]. Taken together, the results would suggest that PC is relatively more important for membrane function than SPM and that choline for neurotransmitter synthesis may be extracted in the first instance from SPM component. The results thus complement the membrane hypothesis of AD . The other interesting feature of our observation is a decrease of greater magnitude in the contents of the acidic phospholipids viz. phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidic acid (PA), while content of the major basic phospholipid i.e. PE did not change (Tables 2 and 3). Decrease in the PI in the brains of the AD patients has already been reported [42–44]. The net result of the compositional changes we observe here (Tables 2 and 3) would be the altered charge distribution in the myelin membrane. The phospholipids are known to be asymmetrically distributed in the two membrane leaflets . Thus the net decrease in the negative charges and relatively lesser decrease in the positive charges that we find here could have major influence on the insulation properties of the myelin membrane. One more interesting features is the decrease in the lysophospholipids (Lyso) and PA which is indicative of decreased phospholipid turnover. We have nothed earlier, similar pattern for rat brain synaptic plasma membranes and microsomes . In this connection, it is of interest to note that in the brains of AD patients the lysophospholipase activity increased significantly [42, 44], and lysophosphospholipid acyl transferase activity increased [42, 44]. This will correlate well with our observation on decreased Lyso content (Tables 2 and 3).
The result of our present studies, taken together with our earlier observations on synaptic plasma membranes and microsomes  suggest that long-term exposure to Al specifically alters the brain lipid/phospholipid metabolism and/or their transfer to various membrane systems. Al may affect these processes by various mechanisms such as creating energy deficiency , forming a complex with ATP where the Al-ATP complex is energy compromised , or by affecting the functions of various enzymes . Role of Al-ATP complex in Ca2+ mediated excitotoxicity and neurotoxicity will ultimately results in neuronal cell death is well recognized, as is the requirement of phospholipases for Ca2+ . Al is known to replace metal ions in many enzyme systems  which in turn could influence the lipid/phospholipid metabolism. Additionally we have shown earlier that prolonged exposure to Al resulted in decreased rates of substrate oxidation in rat brain mitochondria. In particular, the cytochrome oxidase activity decreased significantly . A similar decrease in cytochrome oxidase activity in the brains of AD patients has been reported .
Roth et al.  have reported that reconstituted membrane from the brain lipids of AD patients were thin due to decreased cholesterol content. This is in contrast with our observation that the cholesterol content was actually higher in Al-fed rats. (Table 1) However it may be pointed out that Roth et al., were reporting on the lipid profile of the whole brain regions, whereas we are dealing with purified membrane system. In related studies, we have found that the cholesterol content of the microsomes decreased after Al-treatment [30, 31]. It is thus likely that overall average content of cholesterol of the whole brain might have decreased as reported by Roth et al.; myelin may be a special case where increased cholesterol content may be a compensatory mechanism to ensure the insulation properties following significant alterations in phospholipid profiles (eg. see Tables 2 and 3). We have already shown earlier that changes in lipid/phospholipid profiles drastically impaired the synaptic plasma membrane Na+, K+- ATPase activity  which will get compounded further due to compromised energy transduction and Al-ATP complex formation referred to above [18, 19]. Additionally, the Vmax of cerebral acetylcholinesterase decreased significantly under these experimental conditions . Obviously, these factor will result in impaired signal transmission while the lipid/phospholipid changes in myelin would alter the insulation properties.
Despite the significant changes in lipid / phospholipid profiles (Tables 1,2,3), the membrane fluidity was not altered in the Al-treated group. The molar ratios of TPL/CHL, PC/PE and SPM/PE are the accepted indexes of membrane fluidity [48, 49]. Thus increase in the latter two indicates decreased fluidity, whereas the opposite is true for the TPL/CHL molar ratio . From the data given in Tables 1 and 2, it is clear that the TPL/CHL molar ratio decreased which will decrease the fluidity. However the PC/PE and SPM/PE molar ratios decreased which will increase the fluidity. Thus it is possible that the two opposite effects might have counterbalanced each other and hence there is no apparent net change in membrane fluidity parameters. Interesting to note in this connection is the fact that DPH monitors only the bulk membrane fluidity . Altered membrane fluidity in platelets from AD patients has been reported [43, 51], which is in contrast to our present observations. However once again these authors [43, 51] were measuring the fluidity of the whole cells which can not be extrapolated to purified myelin membrane system described here.
It is well recognized that cerebrosides are major component of myelin . It is possible that long-term Al exposure might have caused alterations even in the content of the cerebrosides in the myelin. However in the present studies, we have not looked at this possibility; further investigations along these lines could provide useful information. Interesting to note in this context is the observation that Al under in vitro conditions increased lipid peroxidation only of the galactolipids .
In conclusion, results of our present studies have brought into focus several parallels in the myelin membrane lipid alterations in Al-treated rats and the AD brains [16, 42, 44]. Such changes in turn can affect the insulation properties leading to memory and cognition dysfunctions which is a common feature of AD [1–7]. The clues that we get from rat studies reported here suggest that it might be of interest to enquire and investigate whether similar changes occur in the myelin membranes in the AD patients.
Effect of long-term Al feeding on the fluidity of the myelin membrane.
Fluorescense Polarization, P
0.254 ± 0.008
0.260 ± 0.003
Fluorescense anisotropy, r
0.186 ± 0.006
0.190 ± 0.002
Limited hindered anisotropy, rα
0.148 ± 0.008
0.153 ± 0.003
Order parameter, S
0.612 ± 0.006
0.622 ± 0.002
- Khachaturian ZA: Diagnosis of Alzheimer's disease. Arch Neurol. 1985, 42: 1097-1105.View ArticlePubMedGoogle Scholar
- Wurtman RJ: Alzheimer's disease. Sci Am. 1985, 252: 62-66.View ArticlePubMedGoogle Scholar
- Hamos JE, DeGennaro LJ, Drachman DA: Synaptic loss in Alzheimer's Disease and other dementias. Neurology. 1989, 39: 355-361.View ArticlePubMedGoogle Scholar
- Soto C, Branes MC, Alvarez J, Inestrosa NC: Structural determinants of the Alzheimer's amyloid β-peptide. J Neurochem. 1994, 63: 1191-1198.View ArticlePubMedGoogle Scholar
- Ashall F, Goate AM: Role of the β-amyloid precursor protein in Alzheimer's disease. Trends Biochem Sci. 1994, 19: 42-46. 10.1016/0968-0004(94)90173-2View ArticlePubMedGoogle Scholar
- Newhouse PA, Potter A, Levin ED: Nicotinic system involvement in Alzheimer and Parkinson's diseases: Implications for therapeutics. Drugs and Ageing. 1997, 11: 206-228.View ArticleGoogle Scholar
- Smith MA: Alzheimer Disease. Int Rev Neurobiol. 1998, 42: 1-54.View ArticlePubMedGoogle Scholar
- Glenner GG: Alzheimer's disease : its proteins and genes. Cell. 1988, 52: 307-313.View ArticlePubMedGoogle Scholar
- Selkoe DJ: Aging brain, aging mind. Sci Am. 1992, 267: 134-142.View ArticlePubMedGoogle Scholar
- Whitehouse PJ, Price DL, Struble RG, Clark AW, Coyle JT, Delon MR: Alzheimer's disease and senile dementia : loss of neurons in the basal forebrain. Science. 1982, 215: 1237-1239.View ArticlePubMedGoogle Scholar
- Schnabel J: Alzheimer's disease : arthritis of the brain?. New Scientist. 1993, 138: 22-26.Google Scholar
- Aarsland D, Larsen JP, Reinvang I, Aasland AM: Effects of cholinergic blockade on language in healthy young women : Implication for the cholinergic hypothesis in dementia of the Alzheimer type. Brain. 1994, 117: 1377-1384.View ArticlePubMedGoogle Scholar
- Smith MA, Sayre LM, Monnier VM, Perry G: Radical AGEing in Alzheimer's disease. Trends Neurosci Sci. 1995, 18: 172-176. 10.1016/0166-2236(95)93897-7. 10.1016/0166-2236(95)93897-7View ArticleGoogle Scholar
- Berlyne GM, Yagil R, Ari JB, Weinberger G, Knopf E, Denovitch GM: Aluminum toxicity in rats. Lancet. 1972, 1: 564-568. 10.1016/S0140-6736(72)90357-1View ArticlePubMedGoogle Scholar
- Deloncle R, Guillard O: Mechanism of Alzheimer's disease: arguments for a neurotransmitter – aluminum complex implication. Neurochem Res. 1990, 15: 1239-1245.View ArticlePubMedGoogle Scholar
- Roth GS, Joseph JA, Mason RP: Membrane alterations as causes of impaired signal transduction in Alzheimer's disease and aging. Trends Neurosci Sci. 1995, 18: 203-206. 10.1016/0166-2236(95)93902-A. 10.1016/0166-2236(95)93902-AView ArticleGoogle Scholar
- McDermott JR, Smith AI, Khalid I, Wisniewiski HM: Brain aluminum in aging and Alzheimer's disease. Neurology. 1979, 29: 809-814.View ArticlePubMedGoogle Scholar
- Exley CA: Molecular mechanism of aluminum induced Alzheimer's disease. J Inorg Biochem. 1999, 76: 133-140. 10.1016/S0162-0134(99)00125-7View ArticlePubMedGoogle Scholar
- Swegert CV, Dave KR, Katyare SS: Effect of aluminum-induced Alzheimer's like condition on oxidative energy metabolism in rat liver, brain and heart metochondria. Mech Ageing Dev. 1999, 112: 27-42. 10.1016/S0047-6374(99)00051-2View ArticlePubMedGoogle Scholar
- Yokel RA: The toxicology of aluminum in the brain: a review. NeuroToxicology. 2000, 21: 813-828.PubMedGoogle Scholar
- Yokel RA, McNamara PJ: Aluminum toxicokinetics: an updated minireview. Pharmacol Toxicol. 2001, 88: 159-167. 10.1034/j.1600-0773.2001.d01-98.xView ArticlePubMedGoogle Scholar
- Sayre LM, Perry G, Atwood CS, Smith MA: The role of metals in neurodegenerative diseases. Cell Mol Biol. 2000, 46: 731-741.PubMedGoogle Scholar
- Crapper DR, Krishnan SS, Quittkat S: Aluminum, neurofibrillary degeneration and Alzheimer's disease. Brain. 1976, 99: 67-80.View ArticlePubMedGoogle Scholar
- Somova LI, Missankov A, Khan MS: Chronic aluminum intoxication in rats: dose-dependent morphological changes. Methods Find Exp Clin Pharmacol. 1997, 19: 599-604.PubMedGoogle Scholar
- Sarin S, Gupta V, Gill KD: Alterations in lipid composition and neuronal injury in primates following chronic aluminum exposure. Biol Trace Elem Res. 1997, 59: 133-143.View ArticlePubMedGoogle Scholar
- Wu YH, Zhou ZM, Xiong YL, Wang YL, Sun JH: Effects of aluminum potassium sulfate on learning, memory, and cholinergic system in mice. Acta Pharmacol Sin. 1998, 19: 509-512.Google Scholar
- Yasui M, Ota K: Aluminum decreases the magnesium concentration of spinal cord and trabecular bone in rats fed a low calcium, high aluminum diet. J Neurol Sci. 1998, 157: 37-41. 10.1016/S0022-510X(98)00075-6View ArticlePubMedGoogle Scholar
- Cucarella C, Montoliu C, Hermenegildo C, Saez R, Manzo L, Minana MD, Felipo V: Chronic exposure to aluminum impairs neuronal glutamate-nitric oxide-cyclic GMP pathway. J Neurochem. 1998, 70: 1609-1614.View ArticlePubMedGoogle Scholar
- Varner JA, Jensen KF, Horvath W, Isaacson RL: Chronic administration of aluminum-fluoride or sodium-fluoride to rats in drinking water: alterations in neuronal and cerebrovascular integrity. Brain Res. 1998, 784: 284-298. 10.1016/S0006-8993(97)01336-XView ArticlePubMedGoogle Scholar
- Pandya JD, Dave KR, Katyare SS: Effect of long-term aluminum feeding on lipid / phospholipid profiles of rat brain synaptic plasma membranes and microsomes. J Alzheimers Dis. 2001, 3: 531-539.PubMedGoogle Scholar
- Pandya JD: Aluminum induced Alzheimer-like condition and membrane function alterations in the rat brain. M.Sc. Dissertation, M. S. University of Baroda, India. 1997Google Scholar
- Agrawal HC, Davison AN: Myelination and amino acid imbalance in the developing brain. In: Biochemistry of the Developing Brain. Edited by: Himmwich W. 1973, I: 143-186. Marcel Dekker, Inc. New YorkGoogle Scholar
- Bilkei GA: Neurotoxic effect of enteral aluminum. Food Chem Toxicol. 1993, 31: 357-361. 10.1016/0278-6915(93)90191-ZView ArticleGoogle Scholar
- Burgoyne RD, Rose SPR: Changes in glycoprotein metabolism in the cerebral cortex following first exposure of dark – reared rats to light. J Neurochem. 1980, 34: 510-517.View ArticlePubMedGoogle Scholar
- Shallom JM, Katyare SS: Altered synaptosomal ATPase activity in rat brain following prolonged in vivo treatment with nicotine. Biochem Pharmacol. 1985, 34: 3445-3449. 10.1016/0006-2952(85)90716-6View ArticlePubMedGoogle Scholar
- Folch J, Lees M, Sloane-Stanley GHA: Simple method for isolation and purification of total phospholipids from animal tissues. J Biol Chem. 1957, 226: 497-509.PubMedGoogle Scholar
- Zlatkis A, Zak B, Boyle JA: A new method for the determination of serum cholesterol. J Lab Clin Med. 1953, 41: 486-492.PubMedGoogle Scholar
- Bartlett GR: Phosphorous assay in column chromatography. J Biol Chem. 1954, 234: 466-468.Google Scholar
- Skipski VP, Barclay M, Barclay RK, Fetzer VA, Good JJ, Archibald FM: Lipid composition of human serum lipoprotein. Biochem J. 1967, 104: 340-361.PubMed CentralView ArticlePubMedGoogle Scholar
- Lowry OH, Rosebrough NJ, Farr AL, Randall RJ: Protein measurement with Folin phenol reagent. J Biol Chem. 1951, 193: 265-275.PubMedGoogle Scholar
- Norton WT: In: Basic Neurochemistry. Edited by: Siegel GJ, Albers RW, Agranoff BW, Katzman R. 1981, 63-92. Little, Brown and Co., BostonGoogle Scholar
- Farooqui AA, Liss L, Horrocks LA: Neurochemical aspects of Alzheimer's disease : involvement of membrane phospholipids. Metab Brain Dis. 1988, 3: 19-35.View ArticlePubMedGoogle Scholar
- Blusztajn JK, Gonzalez-Coviella IL, Logue M, Growdon JH, Wurtman RJ: Levels of phospholipid catabolic intermediates, glycerophosphocholine and glycerophosphoethanolamine, are elevated in brains of Alzheimer's disease but not of Down's syndrome patients. Brain Res. 1990, 536: 240-244. 10.1016/0006-8993(90)90030-FView ArticlePubMedGoogle Scholar
- Farooqui AA, Rapoport SI, Horrocks LA: Membrane phospholipid alterations in Alzheimer's disease. Neurochem Res. 1997, 22: 523-527. 10.1023/A:1027380331807View ArticlePubMedGoogle Scholar
- Albers RW: Cell membrane structure and functions. In : Basic Neurochemistry. Edited by: Siegel GJ, Albers RW, Agranoff BW, Katzman R. 1981, 63-92. Little, Brown and Company, BostonGoogle Scholar
- Kish SJ, Chang LJ, Wilson JM, Distenfuna LM, Noberga N: Brain cytochrome oxidase in Alzheimer's disease. J Neurochem. 1992, 59 (2): 776-779.View ArticlePubMedGoogle Scholar
- Dave KR, Syal AR, Katyare SS: Effect of long-term aluminum feeding on kinetics attributes of tissue cholinesterases. Brain Res Bull. 2002, 58: 225-233. 10.1016/S0361-9230(02)00786-4View ArticlePubMedGoogle Scholar
- Senault C, Yazbeck J, Goubern M, Portet R, Vincent M, Gallay J: Relation between membrane phospholipid composition, fluidity and function in mitochondria of rat brown adipose tissue : Effect of thermal adaptation and essential fatty acid deficiency. Biochim Biophys Acta. 1990, 1023: 283-289. 10.1016/0005-2736(90)90424-MView ArticlePubMedGoogle Scholar
- Bangur CS, Howland JL, Katyare SS: Thyroid hormone treatment alters phospholipid composition and membrane fluidity of the rat brain mitochondria. Biochem J. 1995, 305: 29-32.PubMed CentralView ArticlePubMedGoogle Scholar
- Van Blitterswijk WJ, Van Holven RP, Van Der Meer BW: Lipid structural order parameters (reciprocal of fluidity) in biomembranes derived from steady-state fluorescence polarization measurements. Biochim Biophys Acta. 1981, 644: 323-332. 10.1016/0005-2736(81)90390-4View ArticlePubMedGoogle Scholar
- Zubenko GS, Teply I: Longitudinal study of platelet membrane fluidity in Alzheimer's disease. Biol Psychiat. 1988, 24: 918-924. 10.1016/0006-3223(88)90226-0View ArticlePubMedGoogle Scholar
- Louise Cuzner M, Davison AN: The lipid composition of rat brain myelin and subcellular fractions during development. Biochem J. 1968, 106: 29-34.PubMed CentralView ArticleGoogle Scholar
- Verstraeten SV, Keen CL, Golub MS, Oteiza PI: Membrane composition can influence the rate of Al3+ – mediated lipid oxidation : effect of galactolipids. Biochem J. 1998, 333: 833-838.PubMed CentralView ArticlePubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL.