scholarly journals Dexamethasone influences the lipid fluidity, lipid composition and glycosphingolipid glycosyltransferase activities of rat proximal-small-intestinal Golgi membranes

1988 ◽  
Vol 253 (2) ◽  
pp. 401-408 ◽  
Author(s):  
P K Dudeja ◽  
R Dahiya ◽  
M D Brown ◽  
T A Brasitus
Keyword(s):  
Lipid Composition ◽  
Saturation Index ◽  
Subcutaneous Administration ◽  
Break Point ◽  
Fatty Acyl ◽  
Lipid Fluidity ◽  
Golgi Membranes ◽  
Small Intestinal ◽  
And Control ◽  
Increased Activity

Experiments were performed to examine the effects of subcutaneous administration of the synthetic glucocorticoid dexamethasone (100 micrograms/day per 100 g body wt.) on the lipid fluidity, lipid composition and glycosphingolipid glycosyltransferase activities of rat proximal-small-intestinal Golgi membranes. After 4 days of treatment, Golgi membranes and liposomes prepared from treated rats were found to possess a greater fluidity than their control (diluent or 0.9% NaCl) counterpart, as assessed by steady-state fluorescence-polarization techniques using three different fluorophores. Moreover, analysis of the effects of temperature on the anisotropy values of 1,6-diphenylhexa-1,3,5-triene, using Arrhenius plots, demonstrated that the mean break-point temperatures of treated preparations were 4-5 degrees C lower than those of control preparations. Changes in the fatty acyl saturation index and double-bond index of treated membranes, secondary to alterations in stearic acid, linoleic acid and arachidonic acid, at least in part, appeared to be responsible for the differences in fluidity noted between treated and control Golgi membranes. Concomitant with these fluidity and lipid-compositional alterations, treated membranes possessed higher specific activities of UDP-galactosyl-lactosylceramide galactosyltransferase and CMP-N-acetylneuraminic acid:lactosylceramide sialyltransferase than their control counterparts. Experiments utilizing benzyl alcohol, a known fluidizer, furthermore suggested that the fluidity alteration induced by dexamethasone may be responsible for the increased activity of the former, but not the latter, glycosphingolipid glycosyltransferase.

scholarly journals Dexamethasone-induced alterations in lipid composition and fluidity of rat proximal-small-intestinal brush-border membranes

1987 ◽  
Vol 248 (2) ◽  
pp. 455-461 ◽  
Author(s):  
T A Brasitus ◽  
P K Dudeja ◽  
R Dahiya ◽  
A Halline
Keyword(s):  
Lipid Composition ◽  
Brush Border ◽  
Plasma Membranes ◽  
Subcutaneous Administration ◽  
Break Point ◽  
Molar Ratio ◽  
Brush Border Membranes ◽  
Lipid Fluidity ◽  
Intestinal Brush Border ◽  
Small Intestinal

A series of experiments were conducted to examine the possible effects of subcutaneous administration of the synthetic glucocorticoid dexamethasone (100 micrograms/day per 100 g body wt.) on the lipid fluidity and lipid composition of rat proximal-small-intestinal brush-border membranes. After 4 days of treatment, membranes and their liposomes prepared from treated animals possessed a greater fluidity than did their control (diluent, 0.9% NaCl) counterparts, as assessed by steady-state fluorescence-polarization techniques using several different fluorophores. Examination of the effects of temperature on the anisotropy values of 1,6-diphenylhexa-1,3,5-triene, using Arrhenius plots, moreover, revealed that the mean break-point temperatures of the treated preparations were approx. 3-4 degrees C lower than those of their control-preparation counterparts. Changes in the sphingomyelin/phosphatidylcholine (PC) molar ratio as well as in certain of the fatty acids of the PC fraction of treated membranes, secondary to alterations in membrane PC levels and in lysophosphatidylcholine acyltransferase activities respectively, were also noted after dexamethasone administration. These compositional alterations appeared to be responsible, at least in part, for the differences in fluidity noted between treated and control plasma membranes. These results therefore demonstrate that dexamethasone administration can modulate the lipid fluidity and lipid composition of rat proximal-small-intestinal brush-border membranes.

Ontogeny of basolateral membrane lipid composition and fluidity in small intestine

1989 ◽  
Vol 257 (1) ◽  
pp. G138-G144 ◽  
Author(s):  
S. M. Schwarz ◽  
H. E. Bostwick ◽  
M. D. Danziger ◽  
L. J. Newman ◽  
M. S. Medow
Keyword(s):  
Lipid Composition ◽  
Protein Function ◽  
Specific Activity ◽  
Lipid Analysis ◽  
Basolateral Membrane ◽  
Age Groups ◽  
Membrane Lipid ◽  
Fatty Acyl ◽  
Membrane Lipid Composition ◽  
Small Intestinal

To evaluate physicochemical properties of the small intestinal basolateral cell surface during postnatal development, membranes were isolated from suckling (14-17 days) and weanling-mature (35-49 days) rabbit jejunal and ileal enterocytes at 30- to 40-fold purification (based on Na+-K+-ATPase specific activity) and with limited contamination from coisolated cellular elements. Membrane lipid analysis demonstrated age-dependent reductions and proximal to distal increases in total lipid (per milligram protein). Postnatal increases in membrane total cholesterol of jejunum (suckling vs. mature, 0.18 vs. 0.26 mumol/mg protein; P less than 0.01) and ileum (0.18 vs. 0.31 mumol/mg protein; P less than 0.01) resulted in markedly higher cholesterol-to-phospholipid molar ratios (jejunum, 0.43 vs. 0.73; ileum, 0.43 vs. 0.72 mumol/mg protein; P less than 0.01). Membranes from mature animals had higher relative sphingomeylin and phosphatidylcholine content and, in both age groups, fatty acyl saturation was increased in ileum compared with jejunum. By utilization of the fluorophores 1,6-diphenyl-1,3,5-hexatriene and DL-12-(9-anthroyl)stearic acid, the fluidity of basolateral membranes and liposomes prepared from extracted membrane lipid decreased markedly in mature rabbits. Arrhenius plots demonstrated higher apparent thermotropic transition temperatures of mature membrane lipid. These data therefore demonstrate significant changes in small intestinal basolateral membrane lipid composition and fluidity that occur during the weaning period. Possible relationships to ontogenesis of membrane protein function are discussed.

Protein-lipid interactions in human small intestinal brush-border membranes

1989 ◽  
Vol 257 (5) ◽  
pp. G809-G817
Author(s):  
P. K. Dudeja ◽  
J. M. Harig ◽  
K. Ramaswamy ◽  
T. A. Brasitus
Keyword(s):  
Lipid Composition ◽  
Brush Border ◽  
Gamma Glutamyl Transpeptidase ◽  
Lipid Interactions ◽  
Gamma Glutamyl ◽  
Brush Border Membranes ◽  
Lipid Fluidity ◽  
Intestinal Brush Border ◽  
Small Intestinal ◽  
Glutamyl Transpeptidase

Brush-border membranes prepared from proximal and distal human small intestine were characterized with respect to lipid fluidity, lipid composition, and protein-lipid interactions. Steady-state fluorescence polarization and differential polarized phase fluorometry revealed that the "static" and "dynamic" rotational components of fluidity (assessed by r infinity values of 1,6-diphenyl-1,3,5-hexatriene and r values of 12-anthroylstearate, respectively) were greater in the distal membranes compared with their proximal counterparts. The lipid fluidity of distal brush-border membranes was also greater as measured by excimer/monomer fluorescence ratio intensities of pyrene decanoate. A lower molar ratio of cholesterol/phospholipid in the distal membranes was responsible for these regional fluidity differences. Lipid thermotropic transitions were detected at 26-28 degrees C using 1,6-diphenyl-1,3,5-hexatriene in proximal and distal membranes. Arrhenius plots of p-nitrophenylphosphatase and gamma-glutamyl transpeptidase activities demonstrated breakpoints in the vicinity of the lipid thermotropic transition temperatures (28-30 degrees C), whereas maltase and sucrase yielded a single activity slope over the range of 10-40 degrees C. Moreover, 50 mM benzyl alcohol fluidized proximal brush-border membranes and increased p-nitrophenylphosphatase activity in this membrane. This agent also shifted the phase transition temperature of the membrane and breakpoint temperature of this enzymatic activity from approximately 28 degrees C to 19 degrees C. These findings demonstrate that differences in human small intestinal brush-border membrane lipid fluidity and lipid composition exist between proximal and distal regions of this organ. Furthermore, alterations in fluidity and/or lipid composition modulate p-nitrophenylphosphatase and gamma-glutamyl transpeptidase but not sucrase or maltase activities in these membranes.

scholarly journals Four Weeks of Aerobic Training Affects Cardiac Tissue Matrix Metalloproteinase, Lactate Dehydrogenase and Malate Dehydrogenase Enzymes Activities, and Hepatorenal Biomarkers in Experimental Hyperhomocysteinemia in Rats

2021 ◽  
Vol 22 (13) ◽  
pp. 6792
Author(s):  
Dusan Todorovic ◽  
Marija Stojanovic ◽  
Ana Medic ◽  
Kristina Gopcevic ◽  
Slavica Mutavdzin ◽  
...  
Keyword(s):  
Physical Activity ◽  
Lactate Dehydrogenase ◽  
Malate Dehydrogenase ◽  
Subcutaneous Injection ◽  
Cardiac Tissue ◽  
Albino Rats ◽  
Wistar Albino Rats ◽  
And Control ◽  
Tissue Matrix ◽  
Increased Activity

The aim of this study was to investigate the effect of the application of homocysteine as well as its effect under the condition of aerobic physical activity on the activities of matrix metalloproteinases (MMP), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in cardiac tissue and on hepato-renal biochemical parameters in sera of rats. Male Wistar albino rats were divided into four groups (n = 10, per group): C: 0.9% NaCl 0.2 mL/day subcutaneous injection (s.c.); H: homocysteine 0.45 µmol/g b.w./day s.c.; CPA saline (0.9% NaCl 0.2 mL/day s.c.) and a program of physical activity on a treadmill; and HPA homocysteine (0.45 µmol/g b.w./day s.c.) and a program of physical activity on a treadmill. Subcutaneous injection of substances was applied 2 times a day at intervals of 8 h during the first two weeks of experimental protocol. Hcy level in serum was significantly higher in the HPA group compared to the CPA group (p < 0.05). Levels of glucose, proteins, albumin, and hepatorenal biomarkers were higher in active groups compared with the sedentary group. It was demonstrated that the increased activities of LDH (mainly caused by higher activity of isoform LDH2) and mMDH were found under the condition of homocysteine-treated rats plus aerobic physical activity. Independent application of homocysteine did not lead to these changes. Physical activity leads to activation of MMP-2 isoform and to increased activity of MMP-9 isoform in both homocysteine-treated and control rats.

Use of shape-from-shading to estimate three-dimensional architecture in the small intestinal lumen of celiac and control patients

2013 ◽  
Vol 111 (3) ◽  
pp. 676-684 ◽  
Author(s):  
Edward J. Ciaccio ◽  
Christina A. Tennyson ◽  
Govind Bhagat ◽  
Suzanne K. Lewis ◽  
Peter H.R. Green
Keyword(s):  
Three Dimensional ◽  
Shape From Shading ◽  
Intestinal Lumen ◽  
Small Intestinal ◽  
And Control

scholarly journals Cellular Lipid Composition Affects Sensitivity of Plant Pathogens to Fengycin, an Antifungal Compound Produced by Bacillus subtilis Strain CU12

2014 ◽  
Vol 104 (10) ◽  
pp. 1036-1041 ◽  
Author(s):  
Cody Wise ◽  
Justin Falardeau ◽  
Ingrid Hagberg ◽  
Tyler J. Avis
Keyword(s):  
Bacillus Subtilis ◽  
Lipid Composition ◽  
Plant Pathogens ◽  
Membrane Lipids ◽  
Acyl Chain ◽  
Fatty Acyl ◽  
Subtilis Strain ◽  
Antifungal Compound ◽  
Membrane Pore ◽  
Ergosterol Content

Fengycin is an antimicrobial cyclic lipopeptide produced by various Bacillus subtilis strains, including strain CU12. Direct effects of fengycin include membrane pore formation and efflux of cellular contents leading to cell death in sensitive microorganisms. In this study, four plant pathogens were studied in order to elucidate the role of membrane lipids in their relative sensitivity to fengycin. Inhibition of mycelial growth in these pathogens varied considerably. Analysis of membrane lipids in these microorganisms indicated that sensitivity correlated with low ergosterol content and shorter phospholipid fatty acyl chains. Sensitivity to fengycin also correlated with a lower anionic/zwitterionic phospholipid ratio. Our data suggest that decreased fluidity buffering capacity, as a result of low ergosterol content, and higher intrinsic fluidity afforded by short fatty acyl chain length may increase the sensitivity of microbial membranes to fengycin. Our results also suggest that lower content in anionic phospholipids may increase fengycin insertion into the membrane through reduced electrostatic repulsion with the negatively charged fengycin. The intrinsic membrane lipid composition may contribute, in part, to the observed level of antimicrobial activity of fengycin in various plant pathogens.

Lipid Composition of Liposomal Membrane Largely Affects Its Transport and Uptake through Small Intestinal Epithelial Cell Models

Lipids ◽  
2020 ◽  
Vol 55 (6) ◽  
pp. 671-682 ◽  
Author(s):  
Keisuke Konishi ◽  
Lei Du ◽  
Grégory Francius ◽  
Michel Linder ◽  
Tomoaki Sugawara ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Lipid Composition ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial ◽  
Cell Models ◽  
Liposomal Membrane ◽  
Small Intestinal Epithelial Cell ◽  
Small Intestinal
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