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Biomedical subjects

B Kostka

Publications and source records attributed to B Kostka.

17 recordsLinked to original sources
PubMed1997

Platelet activation by mercuric compounds.

We previously showed that at low concentrations (0.01-10 micromol/l) mercury (Hg) compounds (especially methylmercuric chloride) may act synergistically with physiological agonists to activate platelets and may also cause changes in blood coagulation in experimental animals. Result obtained in this study indicate that the activation of pig blood platelets by methylmercuric chloride (MMC) is not dependent on membrane receptors for fibrinogen and ADP. Furthermore, we have calculated that pig platelets take up approximately 13-fold more Hg than plasma proteins during incubation of platelet-rich plasma with MMC. These findings may explain the recently reported link between vascular events and Hg poisoning.

Journal Article↗
PubMed1983

Effects of mercurial compounds on adenine nucleotides of washed pig platelets.

The effects of methylmercuric chloride, mercuric chloride, and phenylmercuric acetate (10(-6) - 10(-3) mole/liter) on thrombin-induced release of adenine nucleotides from washed pig platelets were investigated. The inhibitory effects of mercurials were always reached when the higher thrombin concentration (0.74 units NIH/ml) was used. Incubation of washed pig platelets with methylmercuric chloride caused a decrease of intracellular level of platelet ATP and statistically significant changes in ATP/ADP ratio.

Adenine Nucleotides↗
PubMed1983

Phenylmercuric acetate and some hemostatic activities of rat platelets.

Fungicide, phenylmercuric acetate (PMA) dose-dependently inhibits in vitro ADP-induced rat platelet primary aggregation. During ex vivo experiments, after oral application of different doses of PMA, the ADP-induced aggregation, clot retraction, bleeding time and clotting time were estimated. Inhibition of platelet activity was found only after a single administration with the high dose of PMA (0.5 LD50). Administration to the rats five times a low dose of PMA (0.2 LD50) and exposure during 5 weeks to the dose of 0.05 LD50 produced hypercoagulation (statistically significant reduction of clotting time) with simultaneous stimulation of platelet activity (stimulation of aggregation, clot retraction and shortening of bleeding time).

Adenosine Diphosphate↗
PubMedDate not supplied

Blood coagulation changes in rats poisoned with methylmercuric chloride (MeHg).

The effects of methylmercuric chloride on the coagulability of blood were studied in rats. The administration of a single dose (17.9 mg Hg/kg) and a repeated dose (5 X 8 mg Hg/kg/day) of this compound resulted in hypercoagulation. The reduction of the clotting time, the increase of fibrinogen level in plasma and changes characteristic of hypercoagulation in the thromboelastographic parameters were observed. Simultaneously, signs of impaired activity of blood platelets: decreased aggregation velocity and clot retraction as well as prolongation of the bleeding time were noticed.

Adenosine Diphosphate↗
PubMedDate not supplied

The in vitro effect of methylmercuric chloride on superoxide dismutase activity of pig platelets.

Incubation of the suspension of washed pig platelets with methylmercuric chloride (MeHg) caused decrease of superoxide dismutase (SOD) activity at the concentrations of MeHg 10(-5)-10(-4) mol/l. We also observed the increase of enzyme activity at low concentrations of MeHg (10(-7)-10(-6) mol/l). MeHg affects the SOD activity similarly to other mercurials which are known to react with sulfhydryl groups, and differentially influence enzymatic systems.

Animals↗
PubMedDate not supplied

Effect of flavonoids on the platelet adhesiveness in repeatedly bred rats.

Decrease of the platelet adhesiveness in rats by some flavonoids has been stated using the method of glass wool filter. The antiadhesive activity of investigated flavonoids may be ordered as follows: nobiletin greater than isorhamnetin 5,7,4'-trimethylether 3-glucoside greater than isorhamnetin 3-glucoside. Methylation of hydroxyl groups of isorhamnetin-3-glucoside markedly increases its antiadhesive activity.

Animals↗