Insulin effect in vitro on human erythrocyte plasma membrane

Luly, Paolo; Baldini, P.; Incerpi, Sandra; Tria, E

doi:10.1007/bf01959904

Cited by 21 publications

(9 citation statements)

References 28 publications

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“…The ghosts were frozen before use, and we observed virtually the same results with fresh and frozen thawed erythrocyte ghosts. Furthermore, the fluorescence polarization values from our control frozen ghosts (P =0.255_+0.037) were in a good agreement with those previously published using fresh erythrocytes by Beguinot et al [19] and by Luly et al [20]. We observed that erythrocyte membranes obtained from uncontrolled Type 1 diabetic patients had a decreased fluorescence polarization value compared to normal when using DPH as a probe.…”

Section: Discussionsupporting

confidence: 81%

“…Luly et al [20] were able to show an elevation of the fluorescence polarization value of normal erythrocyte membrane when incubated with physiological concentration of insulin. Dutta-Roy et al [27] showed that the microviscosity of normal erythrocyte membrane and the filtration time of intact cells were reduced by insulin at physiological concentration in a dose-dependent manner; use of supraphysiological concentration of the hormone reversed the effect of the lower concentration of insulin.…”

Section: Discussionmentioning

confidence: 99%

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Correction by insulin added in vitro of abnormal membrane fluidity of the erythrocytes from Type 1 (insulin-dependent) diabetic patients

et al. 1986

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Summary. Filtrability of erythrocytes obtained from uncontrolled Type I (insulin-dependent) diabetic patients is abnormal, but is corrected by insulin added in vivo or in vitro. As erythrocyte filtrability depends on several determinants, we chose to study a membrane property of erythrocytes from diabetic subjects. Membrane fluidity was studied by fluorescence polarization using a lipophilic probe, the diphenyl-hexatriene and the Coulter Epics V together with a laser Spectra-physics 2000. Fluorescence polarization values obtained for 31 normal subjects (0.253 +0.043 SD) and 31 uncontrolled Type 1 diabetic patients (0.231 + 0.043 SD) were significantly different (p < 0.01). Insulin (2.5.10 -9 mol/1) added in vitro increased Given a relationship between the lipid bilayer and membrane cytoskeleton proteins, this insulin-correctable abnormality of erythrocyte membrane fluidity may be an important determinant of the rheological behaviour of erythrocytes from diabetic patients.Keywords: Membrane, fluorescence polarization, erythrocytes, diabetes, insulin.The erythrocytes &uncontrolled Type 1 (insulin-dependent) diabetic patients have abnormal rheological properties [1][2][3][4]. Modifications in the erythrocyte membrane could be the cause of these theological abnormalities. Biochemical abnormalities have been described [5][6][7] in the membrane, and change in its viscosity have been demonstrated by the fluorescence polarization technique [7][8][9] or electron spin resonance [10]. However, these results have been challenged [11].We have previously observed that the poor filtrability of erythrocytes from uncontrolled Type 1 diabetic patients was rapidly corrected by insulin added in vivo or in vitro [3,4].The aim of this study was therefore to verify whether insulin directly modified the membrane fluidity assessed by fluorescence polarization if such an abnormality was found in cells from diabetic patients. For this purpose, ghosts prepared from erythrocytes originating from uncontrolled Type 1 diabetic patients and matched controls were incubated with and without insulin. Fluorescence polarization was studied with a lipophilic probe, the 1,6 diphenyl-l,3,5 hexatriene (DPH). Subjects and methodsThe subjects were 31 Type I (insulin-dependent) diabetic patients, 20 males and 11 females, aged 26 to 64 years (mean + SD = 44 _+ 16), uncontrolled at the time of the study. None of the patients were smokers, and women did not use oral contraceptive agents. Diabetes duration ranged from 1 to 26 years (mean + SD = 9.6 + 7 years). Two patients had macroproteinuria (i.e. > 500 mg/day) but serum creatinine did not exceed 100 btmol/l in any of the patients. Nine had background retinopathy at fundus examination after papillary dilatation. Patients with proliferative retinopathy or symptoms of cardiovascular disease were excluded from the study. Treatment consisted of two or three insulin injections per day except for two cases treated with one daily insulin injection. Glycosylated haemoglobin values, assessed by microchromatography at...

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Section: Discussionsupporting

confidence: 81%

Section: Discussionmentioning

confidence: 99%

Correction by insulin added in vitro of abnormal membrane fluidity of the erythrocytes from Type 1 (insulin-dependent) diabetic patients

et al. 1986

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“…This is contrary to the results obtained for erythrocyte membranes from healthy subjects by Luly et al [15], who found increased rigidity of erythrocyte membranes treated with insulin. However, our results corroborate those of Bailey et al [16], who observed a similar fluidity increase of rat adipocyte plasma membrane with insulin treatment.…”

Section: Discussioncontrasting

confidence: 99%

Effect of insulin on human erythrocyte membrane fluidity in diabetes mellitus

Bryszewska

Leyko

1983

Diabetologia

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Summary. The effect of insulin in vitro on the fluidity of the human erythrocyte membrane in Type I (insulin-dependent) diabetic patients and healthy control subjects was investigated using a fluorescence technique. It was found that the addition of 10 -9 mol/1 porcine insulin significantly increased fluorescent probe lateral mobility in the membrane lipid layer but did not appear to produce any conformational changes of membrane proteins.Key words: Insulin, erythrocyte membrane, lateral mobility,Interest in hormone interactions with cell membranes has increased considerably during recent years. One hypothesis postulates that changes of membrane lipid structure and microviscosity may play the role of a hormonal information transducer [1].The existence of insulin receptors in erythrocyte membranes has been observed recently [2,3] although their physiological significance requires elucidation [4]. Altered rheological properties of erythrocytes in diabetes have been reported [5][6][7][8][9]. These alterations are related to chariged erythrocyte membrane viscosity and were confirmed by decreased rotational mobility of a fluorescent probe [10] and decreased lateral mobility of pyrene in erythrocyte membranes from insulin-dependent diabetics. Because changes in membrane lipid fluidity are considered to be responsible for information transfer through the membrane, studies were undertaken to investigate the effect of insulin in vitro on the fluidity of erythrocyte membranes in diabetes. Materials and MethodsThe method used to investigate the lateral diffusion of phospholipid molecules in the membrane influenced by insulin was an optical method using the fluorescent label pyrene, which is incorporated deep in the hydrophobic membrane region [11,12]. A measure of the lateral mobility of the probe is the formation rate of excimers during the collision of an excited pyrene molecule and a molecule in the ground state. The excimer fluorescence maximum (470 nm) is well separated from the monomer emission band (396 nm) on the fluorescence spectrum and the intensity ratio I470/I396 of these two peaks is a measure of the lateral mobility of the probe in the membrane (Fig. 1). The wavelength of fluorescence excitation was 339 nm.Blood was taken from 13 Type I (insulin-dependent) diabetic patients all of whom had retinopathy and neuropathy. The mean age of patients was 39.5 + 2.6 years, age of onset of diabetes 24.2 + 2.0 years and insulin dosage 0.88 + 0.12 IU/kg body weight.Blood was taken into 3% sodium citrate after an overnight fast and before the morning insulin and centrifuged at 3000rev/min for 10 rain. After removing plasma and the leucocyte layer, erythrocytes were washed three times with phosphate-buffered saline (PBS: 9 g/1 NaC1 in 10 mmol/1 phosphate buffer, pH 7.4).Erythrocyte membranes were obtained by the method of hypotonic haemolysis [13] and suspended in PBS to give a protein content of 100gg/ml. Pyrene was dissolved in methanol (2.10-3mol/1) and added to the membrane samples at a final probe concentration of 10 ...

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“…Mg 2+ -ATPase (EC 3.6.1.3.) also closely binds to the membrane; its activity is lower after incubation of erythrocytes with linoleic acid (15) but shows no sensitivity to insulin treatment (5) or membrane fluidity (10), in contrast to Na + -K + -ATPase.…”

mentioning

confidence: 98%

“…To act on membrane or intracellular proteins (3), the insulin receptor is believed to trigger various processes through individual or coordinated routes (4). The effect of insulin or receptor (insulin bound) on membrane-bound enzymes has been reported extensively (5)(6)(7)(8), and direct action of the hormone on isolated plasma membranes of liver (9) and erythrocyte (5) has been demonstrated. In erythrocytes the in vitro hormone-receptor interaction could affect membrane fluidity (5), resulting in an alteration of the membrane microenvironment responsible for variations in activity of membrane-bound enzymes [e.g., Na + -K + -ATPase (EC 3.6.1.4.…”

mentioning

confidence: 99%

In Vivo Insulin Effect on ATPase Activities in Erythrocyte Membrane From Insulin-Dependent Diabetics

Rahmani-Jourdheuil

Mourayre

Vague³

et al. 1987

Diabetes

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Na+-K+-dependent ouabain-sensitive ATPase and Mg2+-ATPase have been assayed in the erythrocyte membranes of control subjects and in uncontrolled type I (insulin-dependent) diabetics. A decrease in Na+-K+-ATPase activity was observed in the patients that was significantly correlated with glycemia. The Mg2+-ATPase was increased moderately, and no correlation with glycemia was found. To study the in vivo effect of insulin, ATPase activities were measured in uncontrolled diabetics before and after a 24-h continuous insulin perfusion administered by means of an artificial pancreas. ATPase activities were corrected after normalization of glycemia. It therefore seems that glycemia and/or insulinemia are involved in the regulation of erythrocyte Na+-K+ ouabain-sensitive ATPase and to a lesser extent in that of Mg2+-dependent ATPase.

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Insulin effect in vitro on human erythrocyte plasma membrane

Cited by 21 publications

References 28 publications

Correction by insulin added in vitro of abnormal membrane fluidity of the erythrocytes from Type 1 (insulin-dependent) diabetic patients

Correction by insulin added in vitro of abnormal membrane fluidity of the erythrocytes from Type 1 (insulin-dependent) diabetic patients

Effect of insulin on human erythrocyte membrane fluidity in diabetes mellitus

In Vivo Insulin Effect on ATPase Activities in Erythrocyte Membrane From Insulin-Dependent Diabetics

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