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The involvement of Na+/K+-ATPase in the development of platelet procoagulant response

100%

Tomasiak M., Stelmach H., Rusak T., Ciborowski M., Radziwon P.

2007

vol. 54

issue 3

625-639

In circulation, platelets may come into contact with both exogenous (cardiac glycoside treatment) and endogenously produced inhibitors of Na+/K+-ATPase. We examined whether blocking of platelet Na+/K+-ATPase by ouabain results in generation of procoagulant activity. It was shown that an in vitro treatment of platelets with ouabain (20-200 µM for 20 to 60 min) is associated with an intracellular accumulation of sodium ([Na+]i), generation of a weak calcium signal, and expression of procoagulant activity. The ouabain-induced procoagulant response was dose- and time-related, less pronounced than that evoked by collagen and similar to that produced by gramicidin, not affected by EDTA or aspirin, and strongly reduced in the absence of extracellular Na+ or by hyperosmolality. Flow cytometry studies revealed that ouabain treatment results in a unimodal left shift in the forward and side scatter of the entire platelet population indicating morphological changes of the plasma membrane. The shift was dose related, weaker than that evoked by collagen and similar to that produced by gramicidin. Ouabain-treated platelets express phosphatidylserine (PS). The ouabain-evoked PS expression was dose- and time-dependent, weaker than that produced by collagen and similar to that evoked by gramicidin. Electronic cell sizing measurements showed a dose-dependent increase in mean platelet volume upon treatment with ouabain. Hypoosmotically-evoked platelet swelling resulted in the appearance of procoagulant activity. Thromboelastography measurements indicate that, in whole blood, nanomolar (50-1000 nM, 15 min) concentrations of ouabain significantly accelerate the rate of clot formation initiated by contact and high extracellular concentration of calcium. We conclude that inefficiently operating platelet Na+/K+-ATPase results in a rise in [Na+]i. An increase in [Na+]i and the swelling associated with it may produce PS exposure and a rise in membrane curvature leading to the generation of a procoagulant activity.

Distribution of selected metals and phytochemicals in seeds and peels extract of watermelon (Citrullus lanatus (Thunb.) Mansf.) in Bayelsa State, Nigeria

84%

Ogbuta A., Ukachuku S., Teke E., Ziriki D.

World News of Natural Sciences

2023

vol. 49

156-164

The nutritional benefits of agricultural trash and the therapeutic properties of leftover agricultural product parts are still being thoroughly researched in Africa. This investigation looked at the distribution of specific metals and phytochemicals in Bayelsa state, Nigeria, watermelon (Citrullus lanatus) seed and peel samples. Watermelons (Citrullus lanatus) were picked for their seeds and peel samples after being brought from several gardens in Nigeria's Bayelsa state. Ether acetate was used to extract the samples. The extracts were evaluated at various concentrations, including 10 mg/ml, 5 mg/ml, 2.5 mg/ml, 1.25 mg/ml, 0.625 mg/ml, and 0.3125 mg/ml, for phytochemicals. The phytochemical screening of the ethyl acetate extracts of seed and peel samples, revealed the presence of flavonoids, terpenoids, tannins and cardiac glycosides in seed extracts while flavonoids, phenols, terpernoids, cardiac glycosides, carboxylic acids, quinine and xanthoproteins were detected in peel sample. The samples were digested with an aqua regia and analyzed for metals using atomic absorption spectrometry (AAS). The total concentrations of the metals analyzed varied from 51.05 to 58.40 mg/kg, (5.20±54.73), mean concentrations of the individual metals from result showed iron Fe (28.70-32.60 mg/kg), Mn (11.67-14.14 mg/kg), K (0.24-0.25 mg/kg), Zn (7.89 -9.11 mg/kg), Ni (0.01 -0.03 mg/kg), Cu ( 0.42 -0.48 mg/kg), Mg (1.29 -1.47 mg/kg), Ca (0.56 -0.57 mg/kg) and Pb (0.00-0.01 mg/kg). Iron Fe concentrations were predominant in both seed and peel samples of (Citrullus lanatus). The concentrations of metal in seed and peel samples followed this order Fe>Mn > Zn > Mg >Ca>Cu > K > Ni >Pb and the concentrations of Fe and Mn were relatively higher than WHO daily intake permissible limits in Citrullus lanatus.

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1 Acta Biochimica Polonica

1 World News of Natural Sciences

1 2023

1 2007

1 Ciborowski M.

1 Ogbuta A.

1 Radziwon P.

1 Rusak T.

1 Stelmach H.

1 Teke E.

1 Tomasiak M.

1 Ukachuku S.

1 Ziriki D.

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The involvement of Na+/K+-ATPase in the development of platelet procoagulant response

Distribution of selected metals and phytochemicals in seeds and peels extract of watermelon (Citrullus lanatus (Thunb.) Mansf.) in Bayelsa State, Nigeria