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Sun GY, Sun AY. The effects of chronic ethanol administration on acyl group composition of mitochondrial phospholipids from guinea pig adrenal. RESEARCH COMMUNICATIONS IN CHEMICAL PATHOLOGY AND PHARMACOLOGY 1978; 21:355-8. [PMID: 694232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The acyl groups of diacyl-glycerophosphocholine1 (GPC) and diacyl-glycerophosphoethanolamine (GPE) in guinea pig adrenals are comprised mainly of 16:0, 18:0, 18:1, 18:2 and 20:4(n-6) with only trace amounts of the longer chain polyunsaturated fatty acids. There was an increase in the proportions of 18:2 and a decrease in the 20:4(n-6) of diacyl-GPC and diacyl-GPE with respect to chronic ethanol administration. Acyl group changes were more obvious in diacyl-GPC than in diacyl-GPE. It is conceivable that these changes may lead to an alteration of other membrane transport activities as well as functions of the adrenal gland.
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177
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178
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Corbin DR, Sun GY. Characterization of the enzymic transfer of arachidonoyl groups to 1-acyl-phosphoglycerides in mouse synaptosome fraction. J Neurochem 1978; 30:77-82. [PMID: 621523 DOI: 10.1111/j.1471-4159.1978.tb07037.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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179
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Samorajski T, Strong JR, Sun GY, Sun AY, Seamen R. Dihydroergotoxine and ethanol: physiological and neurochemical variables in male mice. Gerontology 1978; 24 Suppl 1:43-54. [PMID: 145392 DOI: 10.1159/000212297] [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: 12/13/2022] Open
Abstract
The residual effects of dihydroergotoxine mesylate (DHET: active substance of Hydergine), ethanol, and DHET + ethanol were investigated in aging male mice. Prolonged alcohol or DHET consumption was found to prolong hexobarbital sleeping time and increase oxygen consumption. Administration of alcohol combined with DHET inhibited the ability of each drug to prolong hexobarbital sleeping time and increase oxygen consumption. There were no significant differences between groups in forebrain synaptosomal (Na+-K+) adenosine- triphosphatase and acetylcholinesterase activity or cerebellar protein, DNA and RNA content. The relative proportion of phospholipid to protein in isolated myelin of the medulla was significantly reduced, whereas the sphingomyelin content of total phospholipid was highest in alcohol-treated mice. Conocomitant treatment of mice with alcohol combined with DHET prevented the physiological and neurochemical changes caused by alcohol and, in some cases, DHET, administered alone.
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180
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Su KL, Sun GY. The effects of carbamylcholine on incorporation in vivo of [1-14C]arachidonic acid into glycerolipids of mouse brain. J Neurochem 1977; 29:1059-63. [PMID: 599340 DOI: 10.1111/j.1471-4159.1977.tb06509.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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181
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Abstract
The metabolism of a polyunsaturated and a saturated fatty acid in brain membrane phosphoglycerides was examined by injecting simultaneously a mixture of 14C-arachidonate and 3H-stearate into the mouse brain and isolating the microsomal and synaptosomal fractions at 1-40 min after injections. Both types of labeled fatty acids were utilized more readily in the microsomal than the synaptosomal fractions in brain. However, labeled arachidonate was incorporated more rapidly into membrane phosphoglycerides than was stearate. In both subcellular fractions, the relative specific radioactivity (3H and 14C) of diacyl-glycerophosphorylinositol (diacyl-GPI) was higher than other types of phosphoglycerides such as diacyl-glycerophosphorylcholine (diacyl-GPC) and diacyl-glycerophorylethanolamine (diacyl-GPE). Furthermore, the apparent rates of incorporation of radioactivity into diacyl-GPI was more rapid for the 14C-arachidonate than for the 3H-stearate. Results of the experiment have demonstrated obvious differences in metabolism between stearate and arachidonate in brain. The more rapid transfer of arachidonate to diacyl-GPI is probably due to the presence of an acyl transferase system specially active for the transfer of arachidonyl groups to diacyl-GPI.
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182
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Sun GY. Effect of chronic electrical stimulation on incorporation of [1-14C]oleate into glycerolipids of mouse brain. J Neurochem 1977; 28:1385-7. [PMID: 874502 DOI: 10.1111/j.1471-4159.1977.tb12337.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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183
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Sun GY, Creech DM, Corbin DR, Sun AY. The effect of chronic ethanol administration on arachidonyl transfer to 1-acyl-glycerophosphorylcholine in rat brain synaptosomal fraction. RESEARCH COMMUNICATIONS IN CHEMICAL PATHOLOGY AND PHARMACOLOGY 1977; 16:753-6. [PMID: 860087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Enzymatic transfer of arachidonate to synaptosomal diacyl-GPC in a group of rats (n=14) administered 30% ethanol by intragastric intubation for 21 days was 24% higher than controls (n=5) (P less than 0.05). No apparent difference in enzymic activity was observed with respect to different periods of withdrawal (8-24 hrs). The acyl transferase activity in another group of rats (n=5) which were given 15% ethanol as the sole drinking source for 13 months was 58% higher than controls (P less than 0.025). The increase in acyl transferase activity with respect to the two types of chronic ethanol administration may be due to an adaptive mechanism in brain to facilitate the increase in membrane transport activities which are known to occur under the influence of ethanol.
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184
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Leung BS, Sun GY. Acyl group composition of membrane phospholipids in mammary tissues and carcinoma induced by dimethylbenz(a)anthracene. Exp Biol Med (Maywood) 1976; 152:671-6. [PMID: 184477 DOI: 10.3181/00379727-152-39465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phospholipids and their acyl group composition in mammary adenocarcinomas and mammary tissue of the same tumor-bearing animals were investigated. Breast adenocarcinoma induced by dimethybenz(a)anthracene exhibited a phospholipid pattern which was different from that of the mammary tissue. Tumor phospholipids had higher proportions of diacyl-GPI, diacyl-GPE, and alkenylacyl-GPE and a lower proportion of diacyl-GPC than the controls. The acyl groups of most phospholipids in tumors showed a marked increase in the proportion of 18:1 and a decrease in the proportion of 18:2. The fatty acid composition of plasmalogen and triglyceride, however, remained unchanged. In spite of the decrease in the proportion of 18:2, there was no apparent difference in the proportion of 20:4 in most of the phosphoglycerides; however, a significant decrease in this fatty acid was noted in diacyl-GPI. Results of this study demonstrated that the membrane phospholipids of mammary adenocarcinoma were altered in respect to acyl group composition. Changes in physical properties of the cell membrane, in turn, could lead to abnormal manifestation of membrane regulated events in tumor cells.
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185
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Sun GY, Yau TM. Incorporation of (1-14C)oleic acid and (1-14C)arachidonic acid into lipids in the subcellular fractions of mouse brain. J Neurochem 1976; 27:87-92. [PMID: 956857 DOI: 10.1111/j.1471-4159.1976.tb01548.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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186
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Sun GY, Leung BS. Changes in phospholipids and acyl group composition of rat mammary gland during pregnant, lactating, and post-weaning periods. Lipids 1976; 11:322-7. [PMID: 1263775 DOI: 10.1007/bf02544061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The distribution of phospholipids as well as their fatty acid compositions of rat mammary tissues were examined during pregnant, lactating, and post-weaning periods. There was no apparent change in phospholipids and their acyl groups during the early and late pregnant periods. However, tissue phospholipid composition was different during pregnant, early, and late lactating periods. After parturition, there was a marked increase in the proportion of diacyl-glycerophosphorylcholine in the phospholipids of mammary tissue, but this proportion decreased gradually during lactation. The decrease in diacyl-glycerophosphorylcholine during lactation was marked by a corresponding increase in diacyl-glycerophosphorylethanolamie. Although the shorter chain fatty acids of triglycerides were increased during lactation, only a small proportion of these fatty acids was found in the phosphoglycerides. Marked changes in acyl group composition of individual phospholipids are found during these different physiological stages. In general, there was a rapid decrease in 20:4 and an increase in 18:2 in the major phosphoglycerides during parturition. The proportion of 20:4 in the phosphoglycerides remained low throughout the entire lactating period, while that of 18:2 continued to increase 2-3 fold. Most of the changes in acyl group of the phosphoglycerides during lactation returned to normal ca. 10 days after weaning. A possible relationship of the variation of phospholipid and acyl group compositions in mammary tissue to changes in hormonal pattern during different physiological stages is discussed.
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187
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Sun GY, Yau TM. Changes in acyl group composition of diacyl-glycerophosphorylethanolamine, alkenylacyl-glycerophosphorylethanolamine and diacyl-glycerophosphorylcholine in myelin and microsomal fractions of mouse brain during development. J Neurochem 1976; 26:291-5. [PMID: 1255192 DOI: 10.1111/j.1471-4159.1976.tb04479.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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188
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Sun AY, Sun GY. Functional roles of phospholipids of synaptosomal membrane. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1976; 72:169-97. [PMID: 133595 DOI: 10.1007/978-1-4684-0955-0_16] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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189
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Horrocks LA, Sun GY, D’Amato RA. Changes in Brain Lipids During Aging. ADVANCES IN BEHAVIORAL BIOLOGY 1975. [DOI: 10.1007/978-1-4684-0925-3_16] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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190
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Sun GY, Leung BS. Phospholipids and acyl groups of subcellular membrane fractions from human intracranial tumors. J Lipid Res 1974; 15:423-31. [PMID: 4369007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The phospholipids from subcellular fractions of human intracranial tumors were examined. For comparison, microsomes were isolated from a fetal human brain and from the gray matter of adult human brains. The subcellular membranes of tumors had a higher protein-to-phospholipid ratio than the normal brain membranes. The microsomes from tumors had a lower proportion of diacylglycerophosphorylethanolamine and higher proportions of alkenylacylglycerophosphorylcholine and sphingomyelin (plus diacylglycerophosphorylinositol) than microsomes from the gray matter. Also, the ratios of alkenylacylglycerophosphorylethanolamine to diacylglycerophosphorylethanolamine were higher in the tumors than in the normal controls. The acyl groups of ethanolamine phosphoglycerides in tumor microsomes had relatively more 18:1, 18:2, and 20:4(n - 6) and less 18:0, 22:4(n - 6), and 22:6(n - 3) than the adult brain gray matter. Except for the increase in 18:2, acyl group changes in choline phosphoglycerides between tumors and controls were not as extensive as in the ethanolamine phosphoglycerides. The characteristic features of phospholipids and their constituent acyl groups of tumors were often present in all the subcellular fractions. Although the acyl group profiles of the tumor phosphoglycerides were in closer resemblance to the fetal brain than to the adult brain, other differences were observed. Results indicate that neoplastic brain cells are unique in their cellular composition, and consequently they deviate from the normal neurons and glials in metabolism and functions.
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191
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Yau TM, Sun GY. The metabolism of (1-14C)arachidonic acid in the neutral glycerides and phosphoglycerides of mouse brain. J Neurochem 1974; 23:99-104. [PMID: 4854955 DOI: 10.1111/j.1471-4159.1974.tb06921.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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192
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Sun GY, Go J, Sun AY. Induction of essential fatty acid deficiency in mouse brain: effects of fat deficient diet upon acyl group composition of myelin and synaptosome-rich fractions during development and maturation. Lipids 1974; 9:450-4. [PMID: 4407652 DOI: 10.1007/bf02534270] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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193
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Sun GY, Sun AY. Synaptosomal plasma membranes: acyl group composition of phosphoglycerides and (Na+ plus K+)-ATPase activity during fatty acid deficiency. J Neurochem 1974; 22:15-8. [PMID: 4362076 DOI: 10.1111/j.1471-4159.1974.tb12173.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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194
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Sun GY. Phospholipids and acyl groups in subcellular fractions from human cerebral cortex. J Lipid Res 1973; 14:656-63. [PMID: 4742559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Subcellular fractionation of human brain cortex obtained at autopsy yielded microsomal and synaptosome-rich fractions from the gray matter and microsomal and purified myelin fractions from the white matter. The phospholipids of myelin were high in plasmalogens, and the molar ratio of alkenyl acyl sn-glycero-3-phosphorylethanolamine to diacyl sn-glycero-3-phosphorylethanolamine was 4. The acyl groups of the myelin phosphoglycerides were enriched in monoenes (mainly 18:1 and 20:1) and a tetraene, 22:4(n - 6). The phospholipids in the synaptosome-rich fraction were high in diacyl sn-glycero-3-phosphorylcholine, and the molar ratio of the alkenyl acyl sn-glycero-3-phosphorylethanolamine to diacyl sn-glycero-3-phosphorylethanolamine was 0.88. The acyl groups of synaptosomal ethanolamine phosphoglycerides were rich in 22:6(n - 3) but contained a very low amount of 20:1. The lipid composition of microsomes from the gray matter was different from that of microsomes from the white matter but was nearly identical with that of the synaptosome-rich fraction. Except for a slightly lower proportion of alkenyl acyl sn-glycero-3-phosphorylethanolamine and sphingomyelin, the lipid composition of microsomes from the white matter was also similar to that of the myelin. There were also species-related differences between the brain lipid composition of human and subhuman primates and that of the rodents. Furthermore, the brain lipid composition in normal human subjects is rather constant and does not seem to be affected much by individual variations.
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195
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Sun GY. The turnover of phosphoglycerides in the subcellular fractions of mouse brain: a study using (1-14C)oleic acid as precursor. J Neurochem 1973; 21:1083-92. [PMID: 4761697 DOI: 10.1111/j.1471-4159.1973.tb07562.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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196
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Sun GY, Samorajski T. Age differences in the acyl group composition of phosphoglycerides in myelin isolated from the brain of the rhesus monkey. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 316:19-27. [PMID: 4352921 DOI: 10.1016/0005-2760(73)90162-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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197
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Yau TM, Sun GY. Incorporation of (1-14c)-oleic acid into neutral glycerides and phosphoglycerides of mouse brain. Lipids 1973; 8:410-4. [PMID: 4353291 DOI: 10.1007/bf02531717] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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198
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Sun GY, Horrocks LA. Metabolism of palmitic acid in the subcellular fractions of mouse brain. J Lipid Res 1973; 14:206-14. [PMID: 4698268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
After an intracerebral injection of [(14)C]palmitic acid to C57BL/10J mice, the radioactivity in the brains decreased rapidly with time. The incorporated radioactivity was primarily in the 16:0 acyl groups of the diacyl phosphoglycerides at 1 and 3 days after injection. At longer times, increasing proportions of the radioactivity were found in cerebrosides, alkenyl groups, and other acyl groups. The specific radioactivities of the phosphoglycerides were highest in the microsomal fraction at 1 day after injection. The exchange of the diacyl glycerophosphorylcholines and diacyl glycerophosphorylethanolamines between the microsomes and the myelin required 8-14 days. When calculated on the basis of the radioactivity in the 16:0 acyl groups, the half-lives for both of these phosphoglycerides were 6-8 days in all subcellular fractions during the period from 14 to 30 days after injection. The radioactivity in the total lipids from the purified myelin fraction did not decline until more than 14 days after injection because of the reutilization of labeled 16:0 acyl groups for lipid biosynthesis. Recycling of the acyl groups explains the long half-lives reported for myelin phosphoglycerides after injection of [(14)C]acetic acid. Lipids with a relatively high specific radioactivity were lost from the myelin fraction during the purification procedure. The most likely source of these lipids is the most recently formed myelin that is not consolidated into the myelin sheath.
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199
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Sun GY, Sun Y. Phospholipids and acyl groups of synaptosomal and myelin membranes isolated from the cerebral cortex of squirrel monkey (Saimiri sciureus). BIOCHIMICA ET BIOPHYSICA ACTA 1972; 280:306-15. [PMID: 4345143 DOI: 10.1016/0005-2760(72)90098-7] [Citation(s) in RCA: 108] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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200
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Sun GY, Tumbleson ME. Levels of brain lipids in white matter from undernourished Sinclair (S-1) miniature swine. J Neurochem 1972; 19:909-12. [PMID: 5030994 DOI: 10.1111/j.1471-4159.1972.tb01408.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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