1
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Mutually opposite effects of dopamine·HCl and chlorpromazine· HCl on the thickness of liposomal lipid bilayers. Arch Pharm Res 2010; 33:737-44. [DOI: 10.1007/s12272-010-0513-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 03/02/2010] [Accepted: 03/02/2010] [Indexed: 10/19/2022]
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2
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Jang HO, Jeong DK, Ahn SH, Yoon CD, Jeong SC, Jin SD, Yun I. Effects of Chlorpromazine·HCl on the Structural Parameters of Bovine Brain Membranes. BMB Rep 2004; 37:603-11. [PMID: 15479625 DOI: 10.5483/bmbrep.2004.37.5.603] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fluorescence probes located in different membrane regions were used to evaluate the effects of chlorpromazine .HCl on structural parameters (transbilayer lateral mobility, annular lipid fluidity, protein distribution, and lipid bilayer thickness) of synaptosomal plasma membrane vesicles (SPMVs) isolated from bovine cerebral cortex. The experimental procedure was based on the selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) by trinitrophenyl groups, radiationless energy transfer from the tryptophan of membrane proteins to Py-3-Py, and energy transfer from Py-3-Py monomers to 1-anilinonaphthalene-8-sulfonic acid (ANS). In this study, chlorpromazine .HCl decreased the lateral mobility of Py-3-Py in a concentration dependent-manner, showed a greater ordering effect on the inner monolayer than on the outer monolayer, decreased annular lipid fluidity in a dose dependent-manner, and contracted the membrane lipid bilayer. Furthermore, the drug was found to have a clustering effect on membrane proteins.
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Affiliation(s)
- Hye-Ock Jang
- Department of Dental Pharmacology and Biophysics, College of Dentistry and Research Institute for Oral Biotechnology, Pusan National University, Pusan 602-739, Korea
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3
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Affiliation(s)
- D P Muller
- Division of Biochemistry and Genetics, Institute of Child Health, London, United Kingdom
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4
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Chen LC, Wu CY, Chen CF, Chiang CF. Purification of chlorpromazine-sensitive GTPase from rat cerebral cortex. PREPARATIVE BIOCHEMISTRY 1995; 25:183-95. [PMID: 8570568 DOI: 10.1080/10826069508010120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The chlorpromazine-sensitive GTPase from the cell membrane of rat cerebral cortex was purified to homogenity by using DEAE Bio-Gel A agarose, hydroxyapatite and heparin agarose chromatography. The purified chlorpromazine-sensitive GTPase was purified 370-fold to obtain a final specific activity of 40 mumol GTP hydrolyzed2min/mg protein. The purified enzyme was inhibited by chlorpromazine but not by compound 48/80. Magnesium was required for its activity instead of calcium. The purified enzyme had an apparent pH optimum of 8.0, and molecular weight was estimated to be 58,000.
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Affiliation(s)
- L C Chen
- Department of Pharmacology, National Yang-Ming University, Taipei, Taiwan, Republic of China
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5
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Saito M, Iimori Y, Kamoshita S, Yanagisawa M, Sakakihara Y. Effects of peroxisomal beta-oxidation antagonist on 2',3'-cyclic-nucleotide 3'-phosphohydrolase, membrane lipid compositions, and membrane fluidity in C-6 glial cells. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1235:178-82. [PMID: 7756324 DOI: 10.1016/0005-2736(95)80003-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In order to understand the relationship between peroxisomal dysfunction and clinical manifestations of peroxisomal disorders, the effect of thioridazine, a peroxisomal beta-oxidation antagonist, on the differentiation, membrane lipid composition and membrane fluidity of C-6 glial cells was examined. In our study, induction of 2',3'-cyclic-nucleotide 3'-phosphohydrolase (CNP), which was considered to be a membrane-associated enzyme closely associated with myelination, was inhibited with supplementation of thioridazine, followed by an increase in the relative concentration of longer chain fatty acids in cell membrane lipids, indicating that thioridazine causes impaired differentiation in the glial stem cell system. Membrane fluidity of C-6 glial cells was examined using a fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH). The DPH anisotropy value was decreased in the glial cells treated with thioridazine. These results indicate that the alteration of the membrane lipid composition caused by thioridazine affects the differentiation of glial cells via the changes in membrane properties.
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Affiliation(s)
- M Saito
- Department of Pediatrics, Faculty of Medicine, University of Tokyo, Japan
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6
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Lejoyeux M, Daveloose D, Mazière JC, Adès J, Viret J. A spin label study of the membrane effect of various psychoactive drugs in human erythrocytes. Life Sci 1993; 52:PL7-11. [PMID: 8394960 DOI: 10.1016/0024-3205(93)90144-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of psychoactive agents with different clinical actions: three sedative neuroleptics (trifluoperazine, alimemazine tartrate, chlorpromazine), an anticholinergic agent (trihexyphenidyl hydrochloride), two tricyclic antidepressants (imipramine, desipramine) and lithium carbonate on the rotational correlation frequency (V+) of the spin label 16NS has been comparatively investigated in whole human erythrocytes. V+ was about 40% increased by the three neuroleptics, the anticholinergic agent and the antidepressant molecules at 0.2 mM. By contrast, lithium did not induce any significant change in V+ at the same concentrations. It can be suggested that the increase in "membrane fluidity", observed with a wide variety of drugs, is a non specific effect, unrelated to the psychotropic action, that can be ascribed to the amphiphilic properties of the tested drugs.
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Affiliation(s)
- M Lejoyeux
- CRSSA, Division de Biophysique, La Tronche, Grenoble, France
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7
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Zubenko GS, Brenner RP, Teply I. Risk factors for stroke as predictors of platelet membrane fluidity in Alzheimer's disease. Stroke 1991; 22:997-1003. [PMID: 1866768 DOI: 10.1161/01.str.22.8.997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We have previously reported that increased platelet membrane fluidity identifies a subgroup of patients with Alzheimer's disease who have distinct clinical features including an earlier age of symptomatic onset, a more rapidly progressive cognitive decline, and a decreased prevalence of focal electroencephalographic findings. In the current study, these patients also exhibited a decreased prevalence of risk factors for stroke compared with patients who had normal platelet membrane fluidity. Our findings suggest that the platelet membrane abnormality describes a clinical subgroup of patients with Alzheimer's disease who are less likely to have coexisting cerebrovascular disease than the remaining patients who meet clinical consensus criteria for probable Alzheimer's disease.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry, University of Pittsburgh School of Medicine 15213
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8
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Piletz JE, Sarasua M, Chotani M, Saran A, Halaris A. Relationship between membrane fluidity and adrenoceptor binding in depression. Psychiatry Res 1991; 38:1-12. [PMID: 1682966 DOI: 10.1016/0165-1781(91)90047-s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Membrane fluidity and adrenergic receptor binding were studied in platelets of depressed patients before and during treatment with desmethylimipramine to investigate the relationship between the alpha 2-adrenergic receptor and its membrane environment in depression. Most samples came from a previous study in which we observed higher 3H-para-aminoclonidine (3H-PAC) binding in platelets from depressed patients compared to healthy subjects. Fluidity was measured by steady state diphenylhexatriene (DPH) anisotropy in both purified plasma membranes and in intracellular membrane preparations from platelets. No differences were observed in DPH membrane fluidity, per se, indicating that fluidity changes probably do not underlie either the increased alpha 2-adrenergic receptor binding in depression or the normalization of binding during treatment. However, lower intracellular membrane fluidity was correlated with higher binding to 3H-PAC site-1 in healthy subjects, but not in depressed patients. Thus, during depression there may be a disruption in the normal relationship between the adrenergic receptor and its membrane environment.
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Affiliation(s)
- J E Piletz
- Dept. of Psychiatry, MetroHealth Medical Center, Cleveland, OH 44109
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9
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Kaakkola S, Rosenberg PH, Alila A, Erkinjuntti T, Sulkava R, Palo J. Platelet membrane fluidity in Alzheimer's disease and multi-infarct dementia: a spin label study. Acta Neurol Scand 1991; 84:18-21. [PMID: 1656688 DOI: 10.1111/j.1600-0404.1991.tb04896.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The membrane fluidity of platelets isolated from 15 patients with probable Alzheimer's disease (AD), 11 patients with probable multi-infarct dementia (MID), and 7 neurologically healthy controls was studied by electron spin resonance (ESR) spectroscopy employing spin label techniques. Spin label I(12,3) probed the shallow site (hydrophilic region) and spin label I(5, 10) the deeper site (hydrophobic region) of the platelet membrane. With both probes, a significant increase in membrane fluidity was observed in patients with AD and MID, as compared to age-matched controls. However, there were no significant differences in fluidity between AD and MID patients. Our results suggest an increased platelet membrane fluidity in dementias, but the change seems not to be specific to AD.
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Affiliation(s)
- S Kaakkola
- Department of Neurology, University of Helsinki, Finland
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10
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Hajimohammadreza I, Brammer M. Brain membrane fluidity and lipid peroxidation in Alzheimer's disease. Neurosci Lett 1990; 112:333-7. [PMID: 2359533 DOI: 10.1016/0304-3940(90)90226-y] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Membrane fluidity and lipid peroxidation in 4 brain areas from patients with Alzheimer's disease (AD) and matched controls were determined by measuring fluorescence anisotropy of the lipophilic probe 1,6-diphenyl-1,3,5-hexatriene (DPH) and by the thiobarbituric acid test respectively. Fluorescence anisotropy of DPH was not changed in any of the 4 areas in AD compared to controls. Basal levels of malondialdehyde (MDA; an intermediate in the lipid peroxidation process) were also not changed in different brain regions of AD and controls. However, stimulated MDA production determined by incubating tissue with FeSO4 plus H2O2 produced significantly higher MDA levels in AD brain than in controls.
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11
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Abstract
An early-onset, familial form of Alzheimer's disease (AD) has been reported to be linked to a locus on the long arm of chromosome 21 (21q21). Furthermore, duplications in the vicinity of this locus involving the beta-amyloid gene and the proto-oncogene ets-2 have been reported in association with AD. The structural gene for Cu,Zn superoxide dismutase, SOD-1, is located between the beta-amyloid gene and ets-2. For this reason and because SOD-1 is a plausible candidate for a gene that might influence the fluidity of cellular membranes, we determined whether or not the subtype of AD with increased platelet membrane fluidity was associated with an increase in Cu,Zn superoxide dismutase activity.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry, Western Psychiatric Institute and Clinic, Pittsburgh, PA 15213
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12
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Zubenko GS. Endoplasmic reticulum abnormality in Alzheimer's disease: selective alteration in platelet NADH-cytochrome c reductase activity. J Geriatr Psychiatry Neurol 1989; 2:3-10. [PMID: 2742732 DOI: 10.1177/089198878900200102] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Previous evidence suggests that the increase in platelet membrane fluidity associated with a subgroup of patients with Alzheimer's disease results from the accumulation of internal membrane. The specific activities of enzyme markers for selective cell membrane compartments were compared in platelets from subgroups of demented patients with normal or increased fluidity as well as from normal control subjects. A statistically significant change in enzyme activity was observed only for antimycin A-insensitive NADH-cytochrome reductase, a selective marker for smooth endoplasmic reticulum (SER) in platelets. This reduction was limited to the subgroup of demented patients who had increased platelet membrane fluidity, and therefore is not a nonspecific concomitant of neurodegeneration, medication exposure, or chronic illness in general. Since the platelet membrane alteration associated with Alzheimer's disease results from the inheritance of a single major locus, these results suggest that a defect in SER function may exist in brain cells as well as peripheral cells that express this genotype.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry and Geriatric Health Services, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, PA 15213
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Zubenko GS, Huff FJ, Becker J, Beyer J, Teply I. Cognitive function and platelet membrane fluidity in Alzheimer's disease. Biol Psychiatry 1988; 24:925-36. [PMID: 3266076 DOI: 10.1016/0006-3223(88)90227-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Increased platelet membrane fluidity, as reflected by a decrease in the fluorescence anisotropy of diphenylhexatriene in labeled membranes, identifies a clinically distinct subgroup of approximately 50% of patients at our center who meet NINCDS-ADRDA clinical criteria for Alzheimer's disease. In the current study, we compared the cognitive impairments of patients in this subgroup to those observed in the residual subgroup of patients with Alzheimer's disease who had normal platelet membrane fluidity. No significant differences in the number or distribution of deficits in six cognitive domains were observed between the two subgroups. However, in the subgroup with increased platelet membrane fluidity, there were significantly more patients who exhibited dissociation of deficits on tests related to left and right parietal lobe function than in the residual subgroup. Moreover, the cases with dissociation of deficits consisted almost entirely of patients with deficits on tests reflecting left parietal lobe function and no deficit on tests of right parietal lobe function.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry, School of Medicine, University of Pittsburgh, PA
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14
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Abstract
Increased platelet membrane fluidity identifies a prominent subgroup of patients with Alzheimer's disease who exhibit distinct clinical features. In the current longitudinal study, the stability of this membrane characteristic was determined for 15 patients with Alzheimer's disease and 10 healthy elderly controls over a 1-year follow-up period.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry, University of Pittsburgh School of Medicine, PA
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Zubenko GS, Reynolds CF, Perel JM, Decker C, Malinakova I. Platelet membrane fluidity and treatment response in cognitively-impaired, depressed elderly: initial results. Psychopharmacology (Berl) 1988; 94:347-9. [PMID: 3128810 DOI: 10.1007/bf00174688] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A prospective study of response to treatment with nortriptyline was carried out in a group of 14 inpatients with mixed symptoms of depression and dementia. Platelet membrane fluidity, as reflected by the fluorescence anisotropy of DPH labeled membranes, was determined for all 14 drug-free subjects prior to treatment by staff who were blind to clinical and demographic data. Patients who exhibited worsening of their cognitive impairment exhibited "increased" platelet membrane fluidity, an abnormally found in approximately 50% of patients with Alzheimer's disease.
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Affiliation(s)
- G S Zubenko
- University of Pittsburgh School of Medicine, PA 15213
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16
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Zubenko GS, Wusylko M, Cohen BM, Boller F, Teply I. Family study of platelet membrane fluidity in Alzheimer's disease. Science 1987; 238:539-42. [PMID: 3659926 DOI: 10.1126/science.3659926] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene in labeled platelet membranes, an index of membrane fluidity, identifies a prominent subgroup of patients with Alzheimer's disease who manifest distinct clinical features. In a family study, the prevalence of this platelet membrane abnormality was 3.2 to 11.5 times higher in asymptomatic, first-degree relatives of probands with Alzheimer's disease than in neurologically healthy control subjects chosen without regard to family history of dementia. The pattern of the platelet membrane abnormality within families was consistent with that of a fully penetrant autosomal dominant trait. Thus, this abnormality of platelet membranes may be an inherited factor that is related to the development of Alzheimer's disease.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry, University of Pittsburgh, Western Psychiatric Institute and Clinic, PA 15213
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17
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Zubenko GS, Malinakova I, Cohen BM. Temperature dependence of the molecular dynamics of platelet membranes in Alzheimer's disease. Biol Psychiatry 1987; 22:987-94. [PMID: 3607139 DOI: 10.1016/0006-3223(87)90008-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The biophysical properties of platelet membranes from five patients with Alzheimer-type dementia and five neurologically healthy controls, matched for age and sex, were examined by fluorescence spectroscopy employing the fluorescent probes DPH and TMADPH. The anisotropy of DPH has previously been observed to be reduced in platelet membranes of patients with Alzheimer-type dementia. However, Alzheimer's disease was not associated with a significant change in the flow activation energy at either deep or superficial regions of platelet membranes. In addition, the temperature-dependent phase transition observed with TMADPH occurred at the same mean temperature in platelet membranes from the demented and control groups.
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Zubenko GS, Cohen BM, Boller F, Malinakova I, Keefe N, Chojnacki B. Platelet membrane abnormality in Alzheimer's disease. Ann Neurol 1987; 22:237-44. [PMID: 3662454 DOI: 10.1002/ana.410220208] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Fluorescence studies of membrane fluidity were conducted double-blind using platelet and red cell membranes prepared from 24 demented patients with probable Alzheimer's disease and 36 neurologically healthy subjects. The fluidity of the hydrocarbon and lipid-aqueous interface regions of cell membranes was determined at 37 degrees C by fluorescence spectroscopy using the lipid probes 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH), respectively. The rotation rate of TMA-DPH in labeled platelet membranes did not differ between the groups. In contrast, the rotation rate of DPH in labeled platelet membranes from the demented patients (2.15 +/- 0.24 X 10(8)/sec, SD) was greater than that for the normal controls (1.93 +/- 0.13 X 10(8)/sec, SD, p = 3.8 X 10(-5)). This difference was reflected by a reduction in the steady-state anisotropy of DPH in labeled platelets from the demented group (0.1887 +/- 0.0085, SD) when compared to the respective mean for the controls (0.2000 +/- 0.0060, SD; p = 1.3 X 10(-7)). Abnormal membrane fluidity was significantly correlated with severity of dementia, but not with duration of illness or apparent age of onset. The findings do not support the hypothesis that Alzheimer's disease results from a pathological acceleration of the normal aging process, since normal aging is associated with decreased fluidity of cell membranes from platelets, as well as from lymphocytes, hepatocytes, and neurons.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry, University of Pittsburgh School of Medicine, PA
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Abstract
An abnormality of membranes, possibly representing an increase in internal membranes, has been reported in fluorescence spectroscopic and electron microscopic studies of platelets of patients with Alzheimer's-type dementia (AD). To further define this abnormality, the cholesterol and phospholipid content of platelet and erythrocyte membranes was determined and compared for patients with AD and matched control subjects. No significant differences in either cholesterol or phospholipid, per se, were observed in comparing platelets from subjects in the two study groups. However, the ratio of cholesterol to phospholipid was significantly lower (p less than 0.01) in the platelets of patients with AD (9.37 +/- 1.11) than in the platelets of control subjects (10.20 +/- 1.04). Furthermore, the cholesterol to phospholipid ratio correlated significantly (rs = 0.53, p less than 0.01) with a separately determined measure of platelet membrane characteristics, the steady-state anisotropy of DPH (diphenylhexatriene). No differences were observed between the study groups for any of the same parameters measured in erythrocytes, which lack internal membranes. The findings suggest that there is no general abnormality of membrane lipids in Alzheimer's-type dementia. Rather, because normal internal membranes are reported to be low in their cholesterol to phospholipid ratio and in anisotropy of DPH, the results of these studies, together with the results of studies employing electron microscopy, suggest that platelets of patients with AD have an increase in internal membranes. Such membranes, while present in excess, may be normal in composition.
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Zubenko GS, Cohen BM, Reynolds CF, Boller F, Teply I, Chojnacki B. Platelet membrane fluidity identifies a clinical subtype of Alzheimer's disease. Prog Neuropsychopharmacol Biol Psychiatry 1987; 11:683-99. [PMID: 3438464 DOI: 10.1016/0278-5846(87)90004-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
1. The fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) in labeled platelet membranes, an index of membrane fluidity, identifies a prominent subgroup (approx. 50%) of patients with Alzheimer's disease who manifest distinct clinical features. 2. We review an integrated series of studies that explore both the clinical significance of this finding and the biological basis for the platelet membrane alteration.
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Affiliation(s)
- G S Zubenko
- Department of Psychiatry, University of Pittsburgh School of Medicine, PA
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Leli U, Hauser G. Modifications of phospholipid metabolism induced by chlorpromazine, desmethylimipramine and propranolol in C6 glioma cells. Biochem Pharmacol 1987; 36:31-7. [PMID: 3026404 DOI: 10.1016/0006-2952(87)90379-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effects of chlorpromazine (CPZ), desmethylimipramine (DMI) and propranolol (PRO) on phospholipid metabolism in C6 glioma cells were studied by following the incorporation of 32Pi, [U-14C]glycerol, [2-3H]glycerol and [1-14C]oleate into lipids. The drugs produced a dose-dependent increase in the incorporation of 32Pi and [U-14C]glycerol, but not of [1-14C] oleate, into total phospholipids, that reached a plateau at 200 microM CPZ and 500 microM DMI and PRO. The three drugs shifted the incorporation of precursors from neutral [phosphatidylcholine (PC) and phosphatidylethanolamine (PE)] to acidic phospholipids [phosphatidic acid (PA), phosphatidylinositol (PI), phosphatidylglycerol, phosphatidylinositol-4-phosphate (PIP) and phosphatidylinositol-4,5-bisphosphate (PIP2)] in a dose-dependent, qualitatively similar manner. The incorporation of [2-3H]glycerol into diacylglycerol was also depressed markedly by CPZ. Addition of 1 mM 1,2-dioleoylglycerol, 1-oleoyl-2-acetylglycerol or oleate only partially reversed the decrease in PC labeling caused by CPZ. 12-O-Tetradecanoylphorbol-13-acetate counteracted this effect of CPZ completely but greatly increased PC labeling even in the absence of the drug. Polyphosphoinositides rapidly incorporated 32Pi at early times reaching a plateau in about 40 min. The labeling rate of PI was not parallel to that of PIP or PIP2 and continued to increase even after the polyphosphoinositides had reached a plateau. CPZ increased PI labeling much more than that of PIP and PIP2. These data suggest that cationic amphiphilic drugs may act by inhibiting CTP:phosphocholine cytidylyltransferase, thus decreasing incorporation of precursors into PC and PE; inhibiting PA phosphohydrolase with increased formation of phosphatidyl-CMP, the intermediate for the synthesis of acidic phospholipids; and stimulating the inositol exchange reaction, forming a pool of PI that is not available for PIP and PIP2 synthesis.
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Abstract
The biophysical properties of hippocampal membrane preparations from patients with Alzheimer's disease were examined by fluorescence spectroscopy using the membrane lipid probe 1,6-diphenyl-1,3,5-hexatriene (DPH) and its cationic derivative 1-[4-(trimethylamino)-phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH). Results of these experiments suggest that Alzheimer's disease is associated with a biophysical alteration in superficial regions of brain cell membranes, as reflected by the mobility of TMA-DPH. In contrast, no change in the mobility of DPH, which preferentially localizes to the hydrocarbon core, was observed. Although a trend was observed for TMA-DPH mobility to parallel histopathologic severity in hippocampal specimens, the biophysical changes did not appear to reflect a loss of neuronal membranes relative to glial membranes or the presence of senile plaques or neurofibrillary tangles.
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Zubenko GS, Cohen BM. A cell membrane correlate of tardive dyskinesia in patients treated with phenothiazines. Psychopharmacology (Berl) 1986; 88:230-6. [PMID: 2869541 DOI: 10.1007/bf00652246] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Phenothiazine administration to psychiatric patients is associated with an increase in the "structural order" of platelet membranes as determined by steady-state fluorescence polarization measurements with 1,6-diphenyl-1,3,5-hexatriene (DPH), a fluorescent probe that localizes preferentially in the hydrocarbon region of cell membranes (Zubenko and Cohen 1984, 1985a, b). In this study, platelet membranes prepared from a group of psychiatric patients who developed tardive dyskinesia following chronic treatment with phenothiazines exhibited a significant elevation in DPH fluorescence polarization when compared to similar preparations from an otherwise matched group of patients who had no symptoms or history of tardive dyskinesia. The distribution of polarization values obtained for the tardive dyskinesia group displayed minimal overlap with that of an unmedicated, psychiatrically-healthy control group matched for age and gender. The fluorescence polarization of DPH-labelled platelet membranes was not significantly correlated with phenothiazine daily dose or serum cholesterol concentration in the phenothiazine-treated patient groups, or with dyskinesia severity (AIMS rating) in the tardive dyskinesia group. Patient gender and the presence of an affective disorder did not significantly correlate with DPH fluorescence polarization. The potential physiological and clinical significance of these findings is discussed.
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