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Biomedical subjects

E Czarnecka

Publications and source records attributed to E Czarnecka.

At least 37 records · Page 2Linked to original sources
PubMed1983

Effects of ethanol on after--discharges evoked by electrical stimulation of hippocampus in rabbits.

The influence of ethyl alcohol on the after-discharges provoked by electrical stimulation of dorsal hippocampus in rabbits was studied. The after-discharges were registered from frontal cortex reticular mesencephalic substance and contralateral hippocampus. The hippocampus was stimulated seven times every 30 min. in two sessions performed in a 7 days' interval. In the second session ethanol in doses 0.8 g/kg i.v. and 0.4 g/kg p. o. and i. v. was administered. Ethanol administered intravenously in a small dose increase, whereas in a larger dose prevented the increase of after-discharge duration during the session. The influence of ethanol on after-discharges correlated with its initial blood concentration.

Animals↗
PubMed1977

A kinetic study of the pH-dependent properties of the ferric undecapeptide of cytochrome c (microperoxidase).

The ferric form of the haem undecapeptide, derived from horse cytochrome c by peptic digestion, undergoes at least three pH-induced transitions with pK values of 3.4, 5.8 and 7.6. Temperature-jump experiments suggest that the first of these is due to the binding of a deprotonated imidazole group to the feric iron while the second and third arise from the binding of the two available amino groups present (the alpha-NH2 of valine and the epsilon-NH2 of lysine). Molecular models indicate that steric retraints on the peptide dictate that these amino groups may only coordinate to iron atoms via intermolecular bonds, thus leading to the polymerization of the peptide. Cyanide binding studies are in agreement with these conclusions and also yield a value of 3.6 X 10(6) M-1 s-1 for the intrinsic combination constant of CN- anion with the haem. A model is proposed which describes the pH-dependent properties of the ferric undecapeptide.

Animals↗
PubMedDate not supplied

The effect of ethanol and calcium channel antagonists on rabbit EEG.

The influence of nifedipine, verapamil, and cinnarizine on the effect of ethanol on EEG of rabbits (frontal cortex, hippocampus, MRF) was tested. Nifedipine (1.75 mg/kg, IP) and cinnarizine (7.5 mg/kg, IP) were given 30 min before ethanol administration. Verapamil (0.2 mg/kg, IV) was given 15 min before ethanol injection in a dose of 0.8 g/kg IV. Ethanol caused the increase of the frequencies 0.5-4 cps in the recording, as well as a marked decrease of the fastest frequencies. Verapamil prevented ethanol's effect on EEG recording. Cinnarizine antagonized this action to a smaller extent and the influence of nifedipine is transitory and less pronounced.

Animals↗
PubMedDate not supplied

Influence of fluoroquinolones on the central action of ethanol.

The influence of ciprofloxacin, ofloxacin and pefloxacin on acute toxicity of ethanol, ethanol-induced hypothermia, ethanol sleeping time was investigated in mice. Moreover, the combined effect of fluoroquinolones and ethanol on spontaneous locomotor activity, motor coordination in mice and ethanol abstinence syndrome in rats was examined. The fluoroquinolones (20 and 80 mg/kg) were injected intraperitoneally. The drugs were given in single or repeated doses for 7 days. In acute experiments, drugs were given 30 min before ethanol administration. In chronic experiments, the last dose of fluoroquinolones was given 18 h prior to ethanol injection. It has been shown that the fluoroquinolones decrease acute toxicity of ethanol, antagonize its hypothermic effect, decrease ethanol inhibitory effect on motor coordination in mice, and increase ethanol-induced hypermotility in mice and audiogenic seizure response in rats during alcohol abstinence syndrome. Ciprofloxacin and ofloxacin administered repeatedly increase the influence of ethanol on duration of ethanol-induced sleep. The influence of fluoroquinolones on ethanol central action depends on the drug used, its dose and route of administration.

Animals↗
PubMedDate not supplied

An attempt to assess the central action of captopril and enalaprilat.

The influence of captopril and enalaprilat on central nervous system in laboratory animals has been studied. The effects of the drugs on duration of ethanol (4 g/kg i.p.) and thiopental (70 mg/kg i.p.) induced sleep, body temperature, spontaneous locomotor activity and analgesic properties (hot plate and tail-flick test) have been investigated in mice. Captopril (5 and 20 mg/kg i.p.) and enalaprilat (5 and 20 mg/kg i.p.) were used in single administration or repeated one for 10 days. Moreover, pharmaco-EEG profile of captopril and enalaprilat in rabbits has been studied. We have shown that single administration of captopril (both doses) and single or prolonged administration of enalaprilat decreased the duration of ethanol and thiopental-induced sleep. Captopril (5 mg/kg) and enalaprilat (5 and 20 mg/kg) increased pain threshold. Both studied drugs after their single or repeated administration did not influence spontaneous locomotor activity in mice. Captopril and enalaprilat decrease body temperature in mice. Examined ACEIs produce changes in EEG recording, more profoundly exhibited after administration of enalaprilat.

Angiotensin-Converting Enzyme Inhibitors↗
PubMedDate not supplied

The study of organic nitrates, part IV. Chemical and pharmacological study of N-(1-methylethyl)-3-(1-naphthalenyloxy)-2-nitroxypropylamine--potential NO donor.

The reaction of N-(1-methylethyl)-3-(1-naphthalenyloxy)-2-nitroxypropylamine (nitrate analogue of propranolol) with hydrochloride of ethyl ester of L-cysteine at pH 7.7, temp. 37 degrees C was studied. The course of the reaction was monitored by HPLC method. It was found that at these conditions the substrates react and the main product of the decomposition of the nitrate of propranolol analogue is propranolol, nitrate and nitrite ions. The reaction has been described qualitatively and quantitatively. The influence of nitrate analogue of propranolol and propranolol alone on arterial blood pressure and heart rate in normotensive and hypertensive rats (SHR) was also studied. It has been found that both compounds exert a similar effect.

Animals↗
PubMedDate not supplied

Effect of citalopram and buspirone on the antinociceptive action of analgesic drugs.

The influence of citalopram (20 mg/kg i.p.) and buspirone (3 mg/kg i.p.) on analgesic effects of morphine (10 mg/kg i.p.), metamizole (500 mg/kg i.p.) and indomethacin (10 mg/kg) was studied with tail-flick and hot-plate tests on mice. The research studies were further conducted with multiple (14 days) drug dosage. The results indicate that citalopram and buspirone decrease analgesic effects of morphine, metamizole and indomethacin. This mode of action is more pronounced in case of a single dose than after multiple doses.

Analgesics↗
PubMedDate not supplied

Influence of clonazepam and carbamazepine on alcohol withdrawal syndrome, preference and development of tolerance to ethanol in rats.

The effects of clonazepam (0.3 and 1.0 mg/kg or 0.1 mg/kg, b.i.d., 5 days) and carbamazepine (50 and 100 mg/kg or 12.5 and 50 mg/kg b.i.d., 5 days) on alcohol withdrawal syndrome in rats were investigated. Moreover, the influence of clonazepam (0.3 mg/kg, single dose, or repeated doses for 8 days) and carbamazepine (50 mg/kg, single dose, or repeated doses for 8 days) on the development of tolerance to ethanol was also examined. To study the influence of clonazepam and carbamazepine on preference to ethanol, both drugs were administered for 5 days during the last week of the experiment, (clonazepam at 0.1 mg/kg, b.i.d., i.p. and carbamazepine at 12.5 mg/kg, b.i.d, i.p.). Clonazepam and carbamazepine administered at single doses as well as multiple doses diminished the symptoms of withdrawal syndrome. Clonazepam did not prevent the development of tolerance to sleep-inducing and hypothermal action of ethanol, while carbamazepine prevented the development of tolerance to hypnotic effect of ethanol. Carbamazepine clearly reduced preference to ethanol (significantly vs. the control group and vs. the baseline values). Clonazepam also diminished preference to alcohol, but only in comparison with baseline values.

Alcohol Drinking↗