Biomedical subjects

Adam Płaźnik

Publications and source records attributed to Adam Płaźnik.

23 records · Page 2Linked to original sources

PubMedDate not supplied

Age-dependent effects of 5,7-dihydroxytryptamine on serotonin transporter in different brain areas in the rat.

In the present study, we investigated the [(3)H]citalopram binding using a quantitative autoradiography following intracerebroventricular injection of 5,7-dihydroxytryptamine (5,7-DHT) in neonatal and adult male Wistar rats. One group of animals was injected with 5,7-DHT at 3 days after birth while the second group received the neurotoxin at 3 months after birth. Control group was injected with saline. Afterwards, all rats were examined at 4(th) months after birth to determine the serotonin (5-HT) and catecholamines concentrations using the liquid chromatography with electrochemical detection HPLC system and distribution and density of [(3)H]citalopram binding sites in the brain using the quantitative autoradiography. A marked depletion of brain 5-HT was observed in rats lesioned either in postnatal or adult period of life. Rats lesioned in their adult period of life showed dramatic reduction of 5-HT transporter in all investigated brain areas (i.e.the frontal cortex, entorhinal cortex, hippocampus, caudate-putamen, nucleus accumbens and ventral tegmental area). On the other hand, administration of 5,7-DHT to newborn rats failed to reduce 5-HT transporter sites in the ventral tegmental area, and produced only slight or moderate reduction in the nucleus accumbens. Thus, it appears that the mesolimbic ventral tegmental area-nucleus accumbens systems are relatively more resistant to 5,7-DHT neurotoxicity in the early postnatal period.

5,7-Dihydroxytryptamine↗

PubMedDate not supplied

[CYP 2D6 activity profile among patients with depression].

AIM: The aim of this work was to establish the profile of CYP 2D6 activity among patients with depressive disorders, and compare it with the literature data on this activity among healthy volunteers, recruited from the Polish population. METHOD: The debrisoquine test was used to determine CYP 2D6 activity. Debrisoquine metabolic ratio (MR) was determined with the use of high performance liquid chromatography with spectrophotometric detection. Our results were compared with the results obtained with the use of an analogous method in the study performed at the Institute of Cardiology in Warsaw on 154 healthy controls. RESULTS: The percentage of "ultra-fast metabolizers" was 1.03% in the group of patients with depression, and 1.3% in the group of healthy volunteers. The percentages of the "slow metabolizers" in both groups were 5.1% and 5.6% respectively. Also, the percentages of persons considered to be at an increased risk of undesirable side effects from drugs metabolized by CYP 2D6, i.e. persons with debrisoquine metabolic ratio values above 4 were nearly identical in both groups (11.3 and 11.6%). CONCLUSION: The results showed that CYP 2D6 activity profiles were practically identical in both groups. This indicates that there is no relationship between CYP 2D6 gene expression, as measured by the debrisoquine test, and affective disorders morbidity.

Adrenergic Agents↗

PubMedDate not supplied

Effect of kindled seizures on rat behavior in water Morris maze test and amino acid concentrations in brain structures.

The effects of kindled seizures elicited by repeated pentetetrazole (PTZ) injections, on learning and memory in the Morris water maze test and on concentration of brain amino acids, were examined in rats. It was found that kindled seizures (a model of temporal lobe epilepsy) produced a profound decrease in learning and memory accompanied by a selective and long-lasting decrease in hippocampal and striatal concentration of glutamate, glycine and alanine in the striatum (ex vivo measurement). The concentrations of histamine, serine and gamma-aminobutyric acid (GABA) were not selectively affected by kindling. Alower concentration of glutamate and N-methyl-D-aspartate (NMDA) receptor co-agonists in the striatum (glycine and alanine) indicates the general malfunction of the brain glutamatergic system. It is suggested that a selective decrease in hippocampal glutamate concentration may account for deterioration in learning and memory processes in kindled rats, considering the important role of this neurotransmitter in the cognitive processes (e.g. in the long-term potentiation), and the key contribution of the hippocampus to the spatial memory. The intrinsic mechanisms of the reported behavioral effects may involve neuronal damage in the brain limbic structures, secondary to seizure-induced ischemia and hypoxia.

Amino Acids↗

PubMedDate not supplied

Fluoxetine-induced anxiety and nervousness.

The aim of this study was to model fluoxetine-induced increase in anxiety appearing in the initial phase of the treatment with this antidepressant drug. The effects of acute administration of fluoxetine given alone and co-administered with a subthreshold dose of pentetrazole (PTZ), a proconvulsant agent with well recognized anxiogenic properties, were examined in the open field test of neophobia in rats. It was found that a single injection of fluoxetine at the dose of 5 and 10 mg/kg did not change motor and exploratory behavior of rats. Furthermore, fluoxetine (10.0 mg/kg) co-administered with a subthreshold dose of PTZ (10.0 mg/kg) had a strong and selective inhibitory influence on rat exploratory behavior. Pharmacokinetic study did not show any changes in brain concentration of PTZ in fluoxetine-pretreated animals. The central mechanism of the reported effects might involve stimulation of 5-HT2C receptors by fluoxetine in animals with PTZ-induced decrease in the threshold for emotional arousal. The present data describe a new animal model to study the central action of antidepressants reflecting dysphoric-like effects observed in the initial phase of the treatment.

Animals↗

PubMedDate not supplied

Effects of methadone and morphine on c-Fos expression in the rat brain: similarities and differences.

This is the first study designed to compare the pattern of stimulation of c-Fos in selected brain structures after an acute administration of morphine and methadone. Methadone and morphine induced activation of c-Fos protein in the terminal forebrain projecting areas of the brain dopaminergic system, i.e. the striatum and nucleus accumbens. Taking into account generally accepted differences in the potency of pharmacological effects of the two drugs, it is surprising that this effect was most evident after the dose of 5 mg/kg of either drug.

Animals↗