Selective binding of met-hemoglobin to erythrocytic membrane: a possible involvement in red blood cell aging.
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Erythrocyte Aging↗
Biomedical subjects
R Scatena
Publications and source records attributed to R Scatena.
Differences between horse and human haemoglobins in effects of organic and inorganic anions on oxygen binding.
Despite the fact that the horse is one of the more common domesticated animals, there are few reports dealing with the properties of its blood, and no comprehensive study has been performed on the reactivity of horse haemoglobin towards organic and inorganic ions. Here we report data on the effects of the organic phosphates D-glycerate-2,3-bisphosphate (2,3-DPG) and InsP6, and of chloride on the properties of horse haemoglobin. Thus the effect of saturating concentrations of 2,3-DPG on the oxygen affinity of horse haemoglobin is about 60% lower than with human adult haemoglobin under the same experimental conditions. The same applies also to InsP6, whose effect on oxygen binding to horse haemoglobin is decreased by about 55% compared with human adult haemoglobin. On the whole, horse haemoglobin appears to be much less sensitive to organic phosphates than previously believed. These results are discussed in the light of the primary structure of the molecule.
2,3-Diphosphoglycerate↗
Arctic adaptation in whale hemoglobin: interplay of carbon dioxide and temperature in the oxygen unloading.
The functional properties of hemoglobin from the whale Balaenoptera acutorostrata have been characterized as a function of pH, CO2, organic phosphates and temperature. Carbon dioxide effect does not depend on the presence of organic phosphates such as 2,3-DPG and P6-inositol while it is strongly affected by temperature, so that at 37 degrees C it is completely abolished. This, together with the very small delta H of oxygen binding (delta H = -4 to -2 Kcal/mol of oxygen at pH 7.4) has been physiologically interpreted on the basis of the specific metabolic needs of fins and tail which are the place of a great muscular activity.
Adaptation, Physiological↗
Lactate does facilitate oxygen unloading from the hemoglobin of the whale, Balaenoptera acutorostrata, after diving.
The present study reports on a specific effect of lactate on the oxygen binding properties of the hemoglobin from the whale, Balaenontera acutorostrata. In fact 0.1 mM lactate may increase the amount of oxygen unloaded to the tissues as much as 30%. Under these conditions the Bohr shift, of the magnitude of about -1, does not alter the oxygen affinity, but plays an important role in the isohydric transport of carbon dioxide.
Animals↗
Arctic life adaptation--III. The function of whale (Balaenoptera acutorostrata) hemoglobin.
1. The oxygen binding properties of the hemoglobin from the Lesser Rorqual, Balaenoptera acutorostrata, has been investigated with respect to the possible effects of organic phosphates on gas transport in arctic environments. 2. The intrinsic oxygen affinity of the hemoglobin is high and strongly modulated by the effects of organic phosphates. 3. In the absence of organic phosphates, the temperature sensitivity of oxygen binding expressed by the heat of oxygenation, delta H, is -16.2 kcal/mol when corrected for the heat of oxygen in solution. 4. In the presence of organic phosphates there is a marked decrease in the temperature sensitivity delta H approximately -5 kcal/mol). 5. This feature is of great importance for oxygen unloading in the flippers and the tail, where the temperature is lower than the trunk of the whale. 6. Furthermore the organic phosphates strongly increase the Bohr coefficient, delta log P50/delta pH, from less than -0.3 in stripped hemoglobin to about -1.5 when the hemoglobin is saturated with P6-inositol. 7. This feature may be of great physiological importance by reducing the CO2 tension and acidosis after a prolonged dive.
Adaptation, Physiological↗
[Heparin: uses and possibility. Current status].
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Heparin↗
Monocyte oxygenation activities are significantly influenced by non-enzymatic glycosylation of collagen.
The pathophysiology of the acquired extracellular matrix alterations, like non-enzymatic glycosylation (NEG) of proteins secondary to diabetes or ageing, is not well characterized, particularly considering its relationship with leukocytes. We have analysed the influence of collagen NEG on the fundamental function of phagocytic cells, i.e. the production of reactive oxygen species (ROS). To this aim, we considered the activity of polymorphonuclear leukocytes and monocytes incubated in the presence of both non-glycated and glycated collagen. ROS production was monitored by chemi-luminescence (CL), a standardized and sensitive assay of phagocytes oxidative metabolism. All experiments were performed in triplicate on collagen-coated and glycated collage-coated vials. Results showed that PMNs ROS metabolism appeared unrelated to the glycation state of the substrate. Conversely, data regarding zymosan-induced CL by monocytes indicated a significant and intriguing decrease in reactive oxygen metabolism, which appeared greatly compromised by the glycation state of the matrix (monocytes in collagen, 197.4 +/- 31.2 vs. monocytes in glycated collagen, 138.0 +/- 20.4; p < 0.001 expressed as counts/cell/60 min). These data highlight the different role of polymophonuclear and monocytic phagocytes in the pathophysiology of the acquired extracellular matrix alteration secondary to non-enzymatic glycosylation (NEG) of proteins.
Collagen↗
Impaired reactive oxygen metabolism of phagocytic leukocytes in NIDDM patients. A role for non-enzymatic glycosylation of collagen.
Non-enzymatic glycosylation (NEG) of collagen has been previously shown to significantly influence the reactive oxygen metabolism (ROM) of phagocytic cells in healthy subjects. Considering the role of NEG in the pathophysiology of diabetes, we have further analysed the oxidative metabolism of polymorphonuclear cells (PMNs) and monocytes in 23 patients with non-insulin dependent diabetes mellitus in order to better elucidate a possible pathogenic role of NEG of the extracellular matrix in long-term complications of diabetes. Experiments were performed in triplicate on native-collagen and glycated-collagen coated vials, using a chemiluminescence (CL) assay. Results show that PMNs from diabetic patients display a significant increased basal and zymosan-induced CL activity with respect to controls that are not related to the glycation state of the substrate. Conversely, the CL activity of monocytes induced by zymosan shows a decrease in diabetic patients with respect to healthy volunteers (p < 0.05). Moreover, monocyte CL was reduced by the glycated matrix, both in healthy volunteers and in diabetic subjects (p < 0.05 and p < 0.01, respectively). These data highlight a complex role of phagocytic leukocytes in the pathophysiology of extracellular matrix alterations secondary to NEG that are typically present in clinical conditions such as diabetes or ageing.
Collagen↗
Separation of reduced and oxidized glutathione by micellar electrokinetic capillary chromatography.
The separation of reduced and oxidized glutathione at an absolute sensitivity of about 100 pg by micellar electrokinetic capillary chromatography without derivatization is described. The time required for the separation is less than 10 min (the time between two following injections is about 15 min). The separation is characterized by high efficiency and good reliability. A partition mechanism is responsible for the high resolution observed. The method was utilized for the analysis of commercial preparations of glutathione and a good agreement with the expected results was obtained; the oxidation of the commercial glutathione in solution was easily analysed.
Electrophoresis↗
A two-dimensional electrophoresis preliminary approach to human hepatocarcinoma differentiation induced by PPAR-agonists.
Adopting biochemical and proteomic approaches, we investigated the effect of some PPAR-agonists, a new class of differentiating agents, on human hepatocellular carcinoma Hep-G2 cell line. Cancer differentiation was assayed by checking albumin, transferrin and alpha-fetoprotein synthesis. Cell metabolism was studied by NMR spectroscopy of cell culture supernatants and by evaluation of mitochondrial respiratory chain enzyme activities. The two dimensional electrophoresis approach was employed to analyze modifications in the expression of cellular proteins linked to cell phenotype differentiation in the attempt to identify potential diagnostic and prognostic biomarkers of hepatocellular carcinoma. Results indicate that PPAR-agonists are able to act as differentiating inducers in human hepatocellular carcinoma Hep-G2 cell line as well as to inhibit mitochondrial respiratory chain Complex I, provoking a selective derangement of cellular oxidative metabolism. Lastly, two dimensional electrophoresis showed interesting modifications in the pattern of expression of cellular proteins that confirm biochemical data (increase in albumin and transferrin, decrease of alpha-fetoprotein synthesis) and, moreover, emphasize the meaning of these data by the increase of spots indicatively ascribed to HSP70 and catalase.
Bezafibrate↗