Interaction of receptors for prostaglandine E1/prostacyclin and insulin in human erythrocytes and platelets

Duttaroy, Asim K.; Kahn, Nighat N.; Sinha, Asru K.

doi:10.1016/0024-3205(91)90560-x

Cited by 50 publications

(41 citation statements)

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“…Although this activity is higher than that in vivo, we considered this to be a more physiological alternative for nietabolic studies than EDTA or high concentrations of citrate. The PGE, concentration in our incubations is about 0.3x1O4-fold higher than that in plasma (Shimizu et al, 1992), but is calculated to be saturating for the receptor in platelets, which has a Kd of 9.8 nM (Dutta-Roy et al, 1991). Differences between in vivo and in vitro plasma were therefore minimized, but we acknowledge that differences remain (e.g.…”

Section: Discussionmentioning

confidence: 93%

Fuel Choices by Human Platelets in Human Plasma

Guppy

Abas

Neylon

et al. 1997

European Journal of Biochemistry

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Despite the fact that homogeneous preparations of isolated cells are now being used very effectively to study a range of important biochemical questions, it is still not known what combination of fuels and energy-producing pathways is used by cells when offered the complex mixture characteristic of plasma or extracellular fluid. We have developed an in vitro system whereby highly purified and functional human platelets are incubated in human plasma that has been minimally modified from its native state. The concentration of platelets and fuels, and the complexity of fuels in the incubation are similar to those in vivo. The preparation thus represents a reasonable approximation of the physiological condition, considering the complex nature of the system being studied. Measurements carried out simultaneously during the incubation are rates of oxygen consumption, lactate production and fuel oxidation. The data allow the calculation of total ATP turnover, and contributions to this turnover by lactate production and the oxidation of individual fuels. Lactate production accounts for 24% of the ATP turnover. The oxidation of glucose and 3-hydroxybutyrate each account for under S%, palmitate for 21 %, oleate for 7% and acetate for 9%, leaving 32% of the ATP turnover as yet unaccounted for. The results confirm some previous measurements in the literature, but show that data collected under non-physiological experimental conditions can be misleading.Keywords: platelet; oxygen consumption ; plasma; glycolysis ; oxidation.The preparations used for the study of cellular metabolism have progressed over the last 40 years from tissue homogenates and slices to homogeneous preparations of isolated cells. The latter systems are now being used very effectively to study a range of important biochemical questions. However, there is still a question that has never really been adequately addressed, which could have important implications for the relevance of these preparations, and which is fundamental to our understanding of cell biology. This question concerns the combination of fuels and energy-producing pathways used by a cell when it is offered the complex mixture characteristic of plasma or extracellular fluid.Where energy budgets have been presented previously, it is often the case that total ATP turnover has been underestimated due to the omission of any measurement of oxygen consumption. This approach results in overestimates of the contributions of particular fuels and pathways to total ATP turnover as the 'total ATP turnover' figure is too low. For example Petch and Butler (1994) and Neermann and Wagner (1996) conclude that the various pathways of glucose and glutamine utilization account for 100% of ATP turnover in various cell lines in the presence of glucose, glutamine and fetal calf serum. Oxygen consumption was not measured and would almost certainly demonstrate the oxidation of other fuels. Similarly it is now obvious that aerobic glycolysis contributes significantly (20 -50%) to ATP production under aerobic conditions...

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Section: Discussionmentioning

confidence: 93%

Fuel Choices by Human Platelets in Human Plasma

Guppy

Abas

Neylon

et al. 1997

European Journal of Biochemistry

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“…The PGE1 receptor coupled to the G-protein activates adenylate cyclase in human erythrocytes and increases erythrocyte deformality (Dutta-Roy et al 1991). Prostacyclin (PGI) binding to human erythrocyte receptors stimulate cAMP synthesis and ATP release (Sprague et al 2008).…”

Section: Prostaglandins (Pg)mentioning

confidence: 99%

Protein Kinases and Protein Phosphatases as Participants in Signal Transduction of Erythrocytes

Maneva¹,

Maneva-Radicheva²

2012

Protein Kinases

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“…Prostaglandins at nanomolar concentrations control erythrocyte function [2,4,51. Human erythrocytes are unusually sensitive to prostaglandins which, at a concentration of 1 .O M, control erythrocyte deformability, hypotonic haemolysis, and cation exchange [4, 51. Specific interaction between the human erythrocyte membrane and prostaglandin E, (PGE,) has been proposed for several years as PGE, is known to regulate the membrane fluidity of the lipid bilayer, cell deformability, cell shape and surface properties of erythrocyte [2,. These observations suggested the presence of specific PGE, binding sites in the erythrocyte membrane that could mediate the actions of this potent autacoid.…”

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confidence: 99%

“…Stimulation of adenylate cyclase is initiated through the interaction of the hormones/prostaglandins with the specific receptors on the cell surface [5,[12][13][14]. Adenylate cyclase is thought to be one common modality through which prostaglandins exert their biological effects, but growing evidence suggests that the effects may also occur without involving adenylate cyclase [2,151. The human erythrocyte is probably a unique prostaglandin-responsive cell in this regard.…”

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confidence: 99%

“…In human erythrocytes and platelets it has been demonstrated that PGE, and prostaglandin I, (PGI, ) share common receptor sites [2]. PGEJ PGI, binding sites may play a unique regulatory role in erythrocyte function responsible for determining specific rheologic properties, and maintaining normal haemodynamics in vivo [2- man platelets has been isolated and purified [ll].…”

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confidence: 99%

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Prostaglandin‐E₁‐binding sites in rabbit erythrocyte membranes

Duttaroy¹,

Hoque²,

Paterson³

1993

European Journal of Biochemistry

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Prostaglandin El (PGE,) binding sites have been identified on rabbit erythrocyte membranes. The binding of PGE, to the membranes was found to be highly specific, reversible, and saturable.The high-affinity binding sites had a dissociation constant (Kd,,) of 5.6 * 1.2 nM with a binding capacity of 210 5 51 fmol/mg protein, whereas the low-affinity binding sites had a dissociation constant (&) of 22 2 6.4 pM, and a binding capacity of 321 ? 78 pmol/mg protein. Incubation with PGE, did not activate adenylate cyclase in the membranes. Preincubation of rabbit erythrocyte membranes with physiological amounts of insulin (1.5 nM) resulted in an increase of PGE, binding to the membranes from 241 ? 65 to 429 ? 85 fmoumg protein. The insulin-induced increase in PGE, binding was due to an increase in binding sites (both high-affinity and low-affinity binding sites) rather than to an increase in the affinity of the binding sites. Treatment of erythrocyte membranes with PGE, at concentrations (4.0-7.5 nM) which were within the Kd,, value of the high-affinity binding sites, resulted in a significant reduction in membrane fluorescence anisotropy (0.27 ? 0.005-0.21 ? 0.003). Use of higher concentrations (> 15 nM) of PGE, reversed the effect of its lower concentration on the membrane anisotropy.

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Interaction of receptors for prostaglandine E1/prostacyclin and insulin in human erythrocytes and platelets

Cited by 50 publications

References 84 publications

Fuel Choices by Human Platelets in Human Plasma

Fuel Choices by Human Platelets in Human Plasma

Protein Kinases and Protein Phosphatases as Participants in Signal Transduction of Erythrocytes

Prostaglandin‐E₁‐binding sites in rabbit erythrocyte membranes

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Interaction of receptors for prostaglandine E1/prostacyclin and insulin in human erythrocytes and platelets

Cited by 50 publications

References 84 publications

Fuel Choices by Human Platelets in Human Plasma

Fuel Choices by Human Platelets in Human Plasma

Protein Kinases and Protein Phosphatases as Participants in Signal Transduction of Erythrocytes

Prostaglandin‐E1‐binding sites in rabbit erythrocyte membranes

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Product

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Prostaglandin‐E₁‐binding sites in rabbit erythrocyte membranes