Wyniki wyszukiwania

1

Respiratory responses to acute intermittent hypoxia and hypercapnia in awake rats

100%

Sokolowska B., Rekawek A., Jozwik A.

Journal of Physiology and Pharmacology. Supplement

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2008

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tom 59

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nr 6

659-667

2

Influence of MAO-A inhibition on the respiratory response to hypoxia in the conscious rat

100%

Bialkowska M., Zajac D., Rekawek A., Pokorski M.

Acta Neurobiologiae Experimentalis

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2011

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tom 71

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nr 1

Debrisoquine is a peripherally acting monoaminooxidase A (MAO-A) inhibitor. MAO is, in cooperation with the catecholO-methyltransferase (COMT), the main enzyme degradating dopamine in vivo. Dopamine itself is one of the most important neurotransmitters involved in the generation of the respiratory response to hypoxia. Our study seeks to determine whether blockade of the MAO-pathway, resulting in an augmentation of the endogenous dopamine content, could influence the respiratory response to hypoxia in conscious rats. We performed the experiments in 8 male adult Wistar rats (10-11 weeks old, 290-310 g). Minute lung ventilation and its responses to 8 and 12% hypoxic stimuli were measured in a BUXCO whole body plethysmographic chamber. After the control recordings had been taken, debrisoquine (40 mg/kg, i.p.) was injected and the responses to both stimuli were reevaluated after 30 and 60 min. We found that debrisoquine, after 30 min, significantly increased the peak hypoxic ventilatory response (HVR) from 1109 ±161 and 1320±194 to 1744±265 and 2307±259 ml/min/kg for 8% and 12% hypoxia, respectively. However, this effect failed to be long-lasting: 60 min post-injection the peak respiratory response regressed to 1312±135 and 1681 ±105 ml/min/kg, for 8 and 12% hypoxia, respectively. These results indicate that a peripheral blockade of MAO-A increases the HVR. A possible explanation of this phenomenon is the putative stimulatory action of endogenous dopamine (at higher concentrations) or activation by debrisoquine some other stimulatory, non-amine neurotransmitters which do not undergo a MAO-linked oxidation, in the generation of the hypoxic response peripherally at the level of the carotid body. Yet another explanation could be by far unknown, stimulatory influence of debrisoquine on respiration.

3

Mangiferin-a useful antioxidant

88%

Zasada I., Zajac D., Rekawek A., Pozdzik M., Pokorski M.

Acta Neurobiologiae Experimentalis

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2011

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tom 71

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nr 1

Mangiferin is a poliphenolic compound used in the traditional South American and Indian medicine as a panaceum with antibacterial, antitumor, antidiabetic, and antiviral activity. Its main source is the bark and leaves of Mango tree (Magnifera indica L.). Several studies indicate mangiferin antioxidant properties. The purpose of our experiments was to study the possible inhibitory effect of mangiferin on lipid peroxidation, as an expression of its antioxidative capacity. We used the TBA-lipid peroxidation model according to Ernster and Nordenbrand in plasma from rats treated and untreated with mangiferin in both in vivo and in vitro conditions. In the in vitro non-treated rat plasma the amount of peroxidated lipids was 1.114±0.132 µmol/l, the addition of mangiferin (50 µmol/l) diminished this value to 0.720 ±0.025 µmol/l, which is a significant 35% reduction in lipid peroxidation. In plasma from the mangiferintreated rats (300 mg/kg, i.p.), the concentration of reaction products was at the level of 0.352±0.044 µmol/l; being 68% lower than in the untreated rats. We conclude that mangiferin is able to powerfully decrease lipid peroxidation. That indicates that mangiferin’s broad bioactivity should also have to do with its antioxidant properties.

4

Pulmonary surfactant: ultrastructural features and putative mechanisms of aging

76%

Walski M., Pokorski M., Antosiewicz J., Rekawek A., Frontczak-Baniewicz M., Jernajczyk U., Di Giulio C.

Journal of Physiology and Pharmacology. Supplement

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2009

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tom 60

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nr 5

Ograniczanie wyników

2 Acta Neurobiologiae Experimentalis

2 Journal of Physiology and Pharmacology. Supplement

4 Rekawek A.

3 Pokorski M.

2 Zajac D.

1 Antosiewicz J.

1 Bialkowska M.

1 Di Giulio C.

1 Frontczak-Baniewicz M.

1 Jernajczyk U.

1 Jozwik A.

1 Pozdzik M.

1 Sokolowska B.

1 Walski M.

1 Zasada I.

2 2011

1 2009

1 2008

Respiratory responses to acute intermittent hypoxia and hypercapnia in awake rats

Influence of MAO-A inhibition on the respiratory response to hypoxia in the conscious rat

Mangiferin-a useful antioxidant

Pulmonary surfactant: ultrastructural features and putative mechanisms of aging