Changes induced by glucose in the plasma membrane properties of pancreatic islets
Partially purified membranes obtained from rat pancreatic isolated islets preincubated for 3 min with 3.3 and 16.6 mM glucose were labelled with l,6-diphenyl-l,3,5-hexatriene to study fluorescence polarization. Other islets, incubated for 5 min with the same glucose concentration, were extracted and...
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1990
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03037207_v71_n1_p49_Cortizo http://hdl.handle.net/20.500.12110/paper_03037207_v71_n1_p49_Cortizo |
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paper:paper_03037207_v71_n1_p49_Cortizo |
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paper:paper_03037207_v71_n1_p49_Cortizo2023-06-08T15:29:14Z Changes induced by glucose in the plasma membrane properties of pancreatic islets B cell membrane Fatty acids lipid bilayer order Fluorescence polarization Pancreatic islet glucose membrane lipid animal cell article cell membrane fluorescence polarization nonhuman pancreas islet beta cell priority journal rat Animal Cell Membrane Diphenylhexatriene Fatty Acids Fluorescence Polarization Glucose Islets of Langerhans Male Membrane Fluidity Phospholipids Rats Rats, Inbred Strains Support, Non-U.S. Gov't Temperature Thermodynamics Viscosity Partially purified membranes obtained from rat pancreatic isolated islets preincubated for 3 min with 3.3 and 16.6 mM glucose were labelled with l,6-diphenyl-l,3,5-hexatriene to study fluorescence polarization. Other islets, incubated for 5 min with the same glucose concentration, were extracted and phospholipids separated by thin-layer chromatography. The composition of phospholipids of fatty acids was then studied by gas-liquid chromatography. Arrhenius plots of the microviscosity in membranes obtained from islets exhibited two components, a steeper slope below 18 °C and a gentler slope above 18 °C, indicating greater flow activation energy at temperatures below the transition point. Exposure of islets to 16.6 mM glucose significantly increased the flow activation energy (ΔE), below and above the transition point. Islets incubated for 5 min with 16.6 mM glucose showed an increase in the percentage composition of 12 : 0 and 18 : 2 together with a decrease in the 20 : 2 W6 and 22 : 3 W3 fatty acids esterified to phospholipids. Regardless of these changes, no significant alterations occurred in the proportion of saturated fatty acids or in the double bond index; these measurements therefore did not account for the effects of glucose concentration in flow activation energy. The thermotropic changes reported here might be the consequence of some degree of disorder induced by glucose upon the membrane structure. This order alteration could either favor the membrane fusion which occurs during the emiocytosis or only reflects the consequence of such a process. © 1990. 1990 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03037207_v71_n1_p49_Cortizo http://hdl.handle.net/20.500.12110/paper_03037207_v71_n1_p49_Cortizo |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
B cell membrane Fatty acids lipid bilayer order Fluorescence polarization Pancreatic islet glucose membrane lipid animal cell article cell membrane fluorescence polarization nonhuman pancreas islet beta cell priority journal rat Animal Cell Membrane Diphenylhexatriene Fatty Acids Fluorescence Polarization Glucose Islets of Langerhans Male Membrane Fluidity Phospholipids Rats Rats, Inbred Strains Support, Non-U.S. Gov't Temperature Thermodynamics Viscosity |
| spellingShingle |
B cell membrane Fatty acids lipid bilayer order Fluorescence polarization Pancreatic islet glucose membrane lipid animal cell article cell membrane fluorescence polarization nonhuman pancreas islet beta cell priority journal rat Animal Cell Membrane Diphenylhexatriene Fatty Acids Fluorescence Polarization Glucose Islets of Langerhans Male Membrane Fluidity Phospholipids Rats Rats, Inbred Strains Support, Non-U.S. Gov't Temperature Thermodynamics Viscosity Changes induced by glucose in the plasma membrane properties of pancreatic islets |
| topic_facet |
B cell membrane Fatty acids lipid bilayer order Fluorescence polarization Pancreatic islet glucose membrane lipid animal cell article cell membrane fluorescence polarization nonhuman pancreas islet beta cell priority journal rat Animal Cell Membrane Diphenylhexatriene Fatty Acids Fluorescence Polarization Glucose Islets of Langerhans Male Membrane Fluidity Phospholipids Rats Rats, Inbred Strains Support, Non-U.S. Gov't Temperature Thermodynamics Viscosity |
| description |
Partially purified membranes obtained from rat pancreatic isolated islets preincubated for 3 min with 3.3 and 16.6 mM glucose were labelled with l,6-diphenyl-l,3,5-hexatriene to study fluorescence polarization. Other islets, incubated for 5 min with the same glucose concentration, were extracted and phospholipids separated by thin-layer chromatography. The composition of phospholipids of fatty acids was then studied by gas-liquid chromatography. Arrhenius plots of the microviscosity in membranes obtained from islets exhibited two components, a steeper slope below 18 °C and a gentler slope above 18 °C, indicating greater flow activation energy at temperatures below the transition point. Exposure of islets to 16.6 mM glucose significantly increased the flow activation energy (ΔE), below and above the transition point. Islets incubated for 5 min with 16.6 mM glucose showed an increase in the percentage composition of 12 : 0 and 18 : 2 together with a decrease in the 20 : 2 W6 and 22 : 3 W3 fatty acids esterified to phospholipids. Regardless of these changes, no significant alterations occurred in the proportion of saturated fatty acids or in the double bond index; these measurements therefore did not account for the effects of glucose concentration in flow activation energy. The thermotropic changes reported here might be the consequence of some degree of disorder induced by glucose upon the membrane structure. This order alteration could either favor the membrane fusion which occurs during the emiocytosis or only reflects the consequence of such a process. © 1990. |
| title |
Changes induced by glucose in the plasma membrane properties of pancreatic islets |
| title_short |
Changes induced by glucose in the plasma membrane properties of pancreatic islets |
| title_full |
Changes induced by glucose in the plasma membrane properties of pancreatic islets |
| title_fullStr |
Changes induced by glucose in the plasma membrane properties of pancreatic islets |
| title_full_unstemmed |
Changes induced by glucose in the plasma membrane properties of pancreatic islets |
| title_sort |
changes induced by glucose in the plasma membrane properties of pancreatic islets |
| publishDate |
1990 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03037207_v71_n1_p49_Cortizo http://hdl.handle.net/20.500.12110/paper_03037207_v71_n1_p49_Cortizo |
| _version_ |
1768544819221626880 |