Wyniki wyszukiwania

1

Effects of gadolinium chloride on basal flow and compression-induced rapid hyperemia in the rabbit masseter muscle

100%

Turturici M., Roatta S.

Journal of Physiology and Pharmacology

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2014

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tom 65

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nr 3

2

Toxicological and cytophysiological aspects of lanthanides action

100%

Palasz A., Czekaj P.

Acta Biochimica Polonica

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2000

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tom 47

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nr 4

Lanthanides, also called rare-earth elements, are an interesting group of 15 chemically active, mainly trivalent, f-electronic, silvery-white metals. In fact, lanthanides are not as rare as the name implies, except for promethium, a radioactive artificial element not found in nature. The mean concentrations of lanthanides in the earth's crust are comparable to those of life-important elements like iodine, cobalt and selenium. Many lanthanide compounds show particular magnetic, catalytic and optic properties, and that is why their technical applications are so extensive. Numerous industrial sources enable lanthanides to penetrate into the human body and therefore detailed toxicological studies of these metals are necessary. In the liver, gadolinium selectively inhibits secretion by Kupffer cells and it decreases cytochrome P450 activity in hepatocytes, thereby protecting liver cells against toxic products of xenobiotic biotransformation. Praseodymium ion (Pr3+) produces the same protective effect in liver tissue cultures. Cytophysiological effects of lanthanides appear to result from the similarity of their cationic radii to the size of Ca2+ ions. Trivalent lanthanide ions, especially La3+ and Gd3+, block different calcium channels in human and animal cells. Lanthanides can affect numerous enzymes: Dy3+ and La3+ block Ca2+-ATPase and Mg2+-ATPase, while Eu3+ and Tb3+ inhibit calcineurin. In neurons, lanthanide ions regulate the transport and release of synaptic transmitters and block some membrane receptors, e.g. GABA and glutamate receptors. It is likely that lanthanides significantly and uniquely affect biochemical pathways, thus altering physiological processes in the tissues of humans and animals.

3

The effect of pressure on potassium currents in the inner hair cells isolated from guinea-pig cochlea

84%

Kimitsuki T.

Acta Neurobiologiae Experimentalis

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2013

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tom 73

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nr 4

An increase in hydrostatic pressure in the endolymphatic system causes hydrops-related inner ear diseases such as Meniere's disease or low tone sensorineural hearing loss. In the present study, we investigated the effects of pressure exerted on potassium currents in acutely isolated inner hair cells of the guinea-pig cochlea using whole-cell voltage-clamp techniques. By applying negative or positive pressure via the patch pipette using a syringe, intracellular hydropressure was changed between -40 cm H2O to +20 cm H2O. Negative pressure potentiated the amplitude of potassium currents, whereas positive pressure suppressed the amplitude of potassium currents. Gadolinium, a blocker of stretch-activated cation channels, did not influence pressure-dependent changes in potassium currents; however, cinnarizine blocked pressure-dependent changes in potassium currents. The current changes were not dependent on the sign of the pressure change, that is, similar increases in negative pressures (between -10 cm H2O and -40 cm H2O) and similar decreases in positive pressures (between +10 cm H2O and +20 cm H2O) were observed.

4

The effects of freezing on membrane electric potential in winter oilseed rape leaves

84%

Piotrowska G., Filek M., Kacperska A.

Acta Physiologiae Plantarum

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2000

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tom 22

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nr 1

Ograniczanie wyników

1 Acta Biochimica Polonica

1 Acta Neurobiologiae Experimentalis

1 Acta Physiologiae Plantarum

1 Journal of Physiology and Pharmacology

1 Czekaj P.

1 Filek M.

1 Kacperska A.

1 Kimitsuki T.

1 Palasz A.

1 Piotrowska G.

1 Roatta S.

1 Turturici M.

1 2014

1 2013

2 2000

Effects of gadolinium chloride on basal flow and compression-induced rapid hyperemia in the rabbit masseter muscle

Toxicological and cytophysiological aspects of lanthanides action

The effect of pressure on potassium currents in the inner hair cells isolated from guinea-pig cochlea

The effects of freezing on membrane electric potential in winter oilseed rape leaves