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Biomedical subjects

A Romaniuk

Publications and source records attributed to A Romaniuk.

At least 19 recordsLinked to original sources
PubMed2001

Effects of 8-OHDPAT administration into the dorsal raphe nucleus and dorsal hippocampus on fear behavior and regional brain monoamines distribution in rats.

The effects of R(+)-8-hydroxy-dipropylaminotetralin (8-OHDPAT) administration into the dorsal raphe nucleus (DRN) or bilaterally into the dorsal hippocampus (HIP) on fear behavior in a modified version of the light-dark transitions test and regional brain monoamines (NA, DA, 5-HT) and their metabolites (MHPG, DOPAC, 5-HIAA) in the hypothalamus, midbrain central gray matter, amygdala, hippocampus and pons were examined. The experiments were performed on 36 male, 3-month old Wistar rats. Administration of 8-OHDPAT (200 ng) into the DRN reduced time out from the illuminated part of the chamber and time of motionless behavior in the illuminated part, increased the number of returns from the dark to illuminated part and number of head dipping from the dark to illuminated part without effect on time of motionless behavior in the dark part and on time of locomotor activity in the illuminated as well as in dark part of the chamber. HPLC analysis showed reduction of 5-HT content in the midbrain and amygdala, reduction of 5-HIAA content in pons, increased 5-HIAA/5-HT ratio in the hippocampus and increased DOPAC/DA ratio in the hypothalamus, midbrain, hippocampus and pons without affecting the MHPG/NA ratio and NA content. The administration of 8-OHDPAT (100 ng per site) into the HIP reduced time out from the illuminated part of chamber, time of locomotor activity in the illuminated part and head dipping from the dark to illuminated part without effect on the number of returns from the dark to illuminated part, time of locomotor activity in the dark part and time of motionless in the illuminated as well as in the dark part of chamber. HPLC analysis showed reduction of NA content in the hypothalamus, amygdala and pons, increased the MHPG content in all the investigated structures, increased MHPG/NA ratio in all the investigated structures except the hypothalamus. Dopamine content decreased in the hypothalamus and amygdala, and DOPAC/DA ratio increased in the amygdala and hippocampus. Concentrations of 5-HT, 5-HIAA and 5-HIAA/5-HT ratio were unchanged. The results obtained indicate that 8-OHDPAT acting on the pre-synaptic 5-HT1A receptors decreases fear behavior and acting on 5-HT1A post-synaptic receptors increases fear behavior in the light-dark transitions test. The neurochemical base of anxiolytic and anxiogenic effects evoked by 8-OHDPAT is being discussed.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2000

Bicuculline administration into ventromedial hypothalamus: effects on fear and regional brain monoamines and GABA concentrations in rats.

The effects of bicuculline methiodide administration into ventromedial hypothalamus (15 ng per site, bilaterally) on fear behavior and monoamines (NA, DA, 5-HT) and GABA in structures of the brain defensive system (hypothalamus, midbrain gray matter, amygdala, hippocampus and frontal cortex) were studied. Fear behavior was examined in the modified version of light-dark transition test. The time out from the illuminated compartment of chamber, the time spent there and number of returns to the illuminated compartment was measured. Additionally motor activity, i.e., number of crossings and rearings in dark as well as in the illuminated part of compartment, was registered. Blockade of GABAA receptors in the ventromedial hypothalamus resulted in increased fear behavior, i.e. decrease of time out from illuminated compartment and decrease of the time spent there. Motor behavior remained unchanged. HPLC analysis showed reduction of GABA concentration in all investigated brain structures. An increase of NA concentration in all examined structures with exception of the hypothalamus without effect on MHPG/NA was observed as well. Dopamine level remained unchanged, but DOPAC/DA ratio increased in all structures, except frontal cortex. Also HVA/DA ratio increased in the hypothalamus and midbrain. 5-HT concentration increased only in midbrain, 5-HIAA increased in midbrain and in frontal cortex, and 5-HIAA/5-HT ratio increased only in frontal cortex. These results indicate that GABA-ergic and monoaminergic systems remain in functional interactions and that these interactions may play an important role in the neurochemical regulation of fear behavior. The possible mechanism of GABA--monoaminergic interactions is discussed.

Animals↗
PubMed1999

Behavioral and neurochemical alterations evoked by p-Chlorophenylalanine application in rats examined in the light-dark crossing test.

The aim of the present study is to examine the effects of serotonin synthesis inhibition with p-Chlorophenylalanine (p-CPA) in rats on (1) anxiety behavior examined in the light-dark crossing test and, (2) regional brain concentration of monoamines (NA, DA and 5-HT) and their metabolites (MHPG, DOPAC, HVA and 5-HIAA) as well as GABA in the hypothalamus, amygdala, hippocampus, midbrain central gray matter and the frontal cortex. Treatment of animals with p-CPA produced a significant increase in time out from the illuminated part of the chamber and in time of locomotor activity in the illuminated part of the chamber. HPLC analysis showed a significant reduction of 5-HT and 5-HIAA concentration in all examined brain regions with the exception of the frontal cortex. Additionally, a significant decrease in DA and its metabolites, DOPAC and HVA occurred in the hypothalamus and amygdala. Moreover, we observed a significant decrease in frontal cortex NA concentration after p-CPA administration. The results of our study suggest that administration of p-CPA is effective in reduction of anxiety through depletion of 5-HT accompanied by diminution of catecholamines, especially DA and its metabolites in the main emotional brain regions.

Animals↗
PubMed1998

Social interactions, brain monoamines, and GABA alterations in MFB-lesioned cats.

The effects of denervation of central noradrenergic system on the interpartner relationships of adult cats were examined in a predatory test in the competitive situation for paired animals. Direct administration of the noradrenaline neurotoxin, N-2-chloroethyl-N-ethyl-2-bromobenzylamine (DSP-4 12 microg) into the medial forebrain bundle (MFB) of submissive cats changed previously established dominant-submissive relationship. Biochemical analysis demonstrated a significant reduction of noradrenaline (NA) concentration in the hypothalamus (AH), amygdala (AM), hippocampus (HC), and frontal cortex (CTX), and elevation of NA content in the midbrain central gray matter (CG) in MFB-lesioned cats. Simultaneously, DSP-4-induced lesions exerted significant decrease of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) content in AH, CG, HC and CTX, and increased GABA level in AH, CG, AM, and HC. These results suggest that a coincident decrease of NA metabolism and increase of GABA metabolism led to fear drive reduction.

Animals↗
PubMed1997

Behavioral and biochemical alterations in median and dorsal raphe nuclei lesioned cats.

Ten days after 5, 7-dihydroxytryptamine (5,7-DHT) administration into the median (MRN) and dorsal (DRN) raphe nuclei, preceded by nomifensine IP, an increase of post-carbachol growling response occurred. There were no differences in the amount of locomotor activity on any post-lesion day. In predatory test in a competitive situation for paired cats ten and fifteen days after 5,7-DHT administration into the MRN and DRN of submissive cats, formerly submissive animals, engage in the fight for domination after lesions. HPLC analysis showed in all lesioned groups a significant reduction of 5-HT and 5-HIAA in the hypothalamus, midbrain, amygdala and hippocampus after the MRN lesion and in the hypothalamus, amygdala, hippocampus and frontal cortex after the DRN lesion. After the MRN and DRN lesion no spontaneous aggressive behavior occurred in any cat. The results indicate that both raphe nuclei participate in the central regulation of affective and predatory aggression in the cat.

5,7-Dihydroxytryptamine↗
PubMed1995

Fear induced by the blockade of GABAA-ergic transmission in the hypothalamus of the cat: behavioral and neurochemical study.

Intrahypothalamic injections of d-Tubocurarine (DT) and bicuculline (BM) in the cat produced a fear reaction characterized by terrific mewing, increased locomotor activity, jumps and attempt to escape from the chamber, pupillary dilatation, increased respiratory rate, and sometimes urination and defecation. HPLC analysis showed a significant increase in the noradrenergic system activity in the emotional brain areas (hypothalamus, midbrain, amygdala) and frontal cortex at the time of the fear drive. No changes in the cat's behavior and in the monoaminergic systems activity occurred after muscimol+d-Tubocurarine injections into the hypothalamus. Similar behavioral and neurochemical effects evoked by DT and BM suggest that the fear response evoked by DT does not result from the blockade of N-cholinergic transmission but rather from their action on GABAA receptor complex. The results obtained indicate that the central triggering mechanism for fear drive depends on the blockade of GABAA-ergic transmission.

Amygdala↗
PubMed1995

Rejection of cartilage formed by transplanted allogeneic chondrocytes: evaluation with monoclonal antibodies.

Cellular infiltrates participating in rejection of cartilage formed by transplanted allogeneic rat epiphyseal chondrocytes were evaluated immunohistochemically using a panel of different monoclonal antibodies. One week after transplantation, the grafts were surrounded by numerous class II MHC+ (OX6+, OX17+), CD4+ (W3/25+), and W3/13+ cells as well as some ED1+ monocytes/macrophages. Only a few T (OX19+) and B (HIS14+) cells were present. The number of class II MHC+ cells and ED1+ monocytes/macrophages did not change significantly in the course of rejection whereas the number of CD4+ and W3/13+ cells gradually decreased. On the other hand, there was a significant increase in the number of CD8+ (OX8+) cells. CD8+ cells accumulated close to the transplants and some of them penetrated cartilage matrix suggesting that they might be involved in chondrocyte killing. After 3 months, cartilage was almost completely destroyed and the intensity of infiltrations was markedly decreased. Fibrous connective tissue predominated, however, some class II+ as well as few ED1+, CD4+ and CD8+ cells were still present adjacent to the cartilage remnants. At the time of transplantation, chondrocytes were endowed with RT1.D class II antigen (OX17+), but they did not react with OX6 mAb (monoclonal antibody) recognizing the RT1.B class II molecule. However, after 1 week, some chondrocytes reacted with OX6 mAb and the number of RT1.B positive chondrocytes increased in the course of cartilage rejection.

Animals↗
PubMed1995

Social interactions in cats: regional brain monoamine distribution in dominant and submissive cats.

Regional brain concentration of monoamines (NA, DA and 5-HT) and their metabolites (MHPG, DOPAC, HVA and 5-HIAA) were measured in dominant and submissive cats in a predatory competition test and in predatory behaviour of single cats. A submissive position in predatory hierarchy produced an increase in concentration of NA in the hypothalamus, a decrease of DA, 5-HT, MHPG and MHPG/NA ratio in the hippocampus and a decrease of 5-HT in the prefrontal cortex in comparison with dominant cats. In the predatory test the social situation increased the concentration of DA and its metabolites in the hypothalamus of the submissive and dominant cats as compared to single cats. Additionally, a diminution of NA and MHPG concentration in the midbrain in dominant cats compared to single animals in the predatory situation was observed. The data obtained demonstrate a considerable differentiation in the effects of predatory aggression and predatory behaviour in a social situation on brain distribution of monoamines. The results indicate that predatory behaviour in single and paired cats is regulated by different catecholamine mechanisms.

Animals↗
PubMed1994

The effects of dorsal and ventral noradrenergic system lesions with DSP-4 on emotional-defensive behavior and regional brain monoamines content in the cat.

As a result of selective lesions of dorsal (DB) and ventral (VB) noradrenergic system (DSP-4 i.c.) it was observed that these two systems are functionally differentiated and only DB participates in the regulation of post-carbachol emotional-defensive behavior in the cat. Following DB lesion an increase in emotional-defensive excitation occurred and HPLC analysis showed a significant reduction of NA concentration in the posterior hypothalamus, midbrain central gray matter and frontal cortex and decreased turnover of 5-HT in all "emotional brain areas" (hypothalamus, midbrain, amygdala, hippocampus) and frontal cortex. Following VB lesion there were no significant changes of post-carbachol defensive behavior and HPLC analysis showed a significant reduction of NA in the anterior and posterior hypothalamus, midbrain central gray matter and amygdala and an increased turnover of 5-HT in the posterior hypothalamus and midbrain central gray matter. The results obtained can be interpreted in relation to functional interactions between the NA and 5-HT systems.

Adrenergic Agents↗
PubMed1994

Social interactions in rats: behavioral and neurochemical alterations in DSP-4-treated rats.

Noradrenergic neurotoxin DSP-4, preceded by zimelidine to prevent serotonin depletion, was administered IP to rats behaving in a defensive-submissive manner in a resident-intruder paradigm. Computer-based ethological analysis revealed the decrease of frequency and duration of defensive episodes and marked increase of offensive aggression. This might suggest an increase of aggressiveness and therefore support the notion of an inhibitory role of the noradrenergic system in aggressive behavior independently of the model used. Dramatically changed attitude toward the partner might also result from fear reduction or inadequate responsiveness to environmental factors because DSP-4-treated rats explored more than controls in stressogenic, highly illuminated area. HPLC analysis showed significant reduction of noradrenaline (NA) concentration in amygdala, hypothalamus, hippocampus, and frontal cortex. Simultaneously there occurred a considerable decrease in dopamine (DA) and serotonin (5-HT), and their metabolite levels. This suggests an attenuated activity of the DA and 5-HT systems that we consider as an effect secondary to NA depletion, which reflects the functional interactions between DA, 5-HT, and NA systems.

Aggression↗
PubMed1990

Behavioral and neurochemical alterations following 5,6-dihydroxytryptamine administration into the median raphe nucleus in the cat.

The 5,6-dihydroxytryptamine administration into the median raphe nucleus in the cat resulted in an increase in the carbachol-induced emotional-defensive behavior and a decrease of 5-hydroxyindoleacetic acid and dopamine level in the hypothalamus, midbrain and amygdala. Lesions of median raphe nucleus resulted in similar, but more subtle alterations of post-carbachol emotional-defensive response similarly to dorsal raphe nucleus lesions, and they had also different biochemical effects in the "emotional regions" of the brain (hypothalamus, midbrain, amygdala). The absence of differentiated participation of both dorsal raphe nucleus and median raphe nucleus in the regulation of different aspect of the cat's behavior, and the role of both nuclei in the modulation of post-carbachol response is discussed.

5,6-Dihydroxytryptamine↗
PubMed1990

Further evidence against using sorbitans in the brain mechanisms investigation.

In both experimental groups an intraperitoneal injection of a single dose of 450 mg/kg p-Chlorophenylalanine (p-CPA) containing 1.0% arabic gum and 450 mg/kg p-CPA containing 0.1% Tween 80 resulted in a similar drop of the serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) level in the anterior (HA) and posterior (HP) hypothalamus, midbrain (GC) and amygdala (AM). Despite the fact that just the same decrease in the 5-HT turnover occurred in both groups, only in the group treated with p-CPA containing arabic gum a rise in postcarbachol emotional-defensive response was observed. The level of dopamine (DA) did not change in both groups. The level of noradrenaline (NA) in the p-CPA with arabic gum treated group was not subject to any change, whereas in the p-CPA with Tween 80 treated group its considerable decrease was noticed, though no essential statistical differences appeared: in HA by 26%, in HP by 38%, in GC by 23% and in AM by 62% as compared to control group (NaCl treated) and in HA by 35%, in HP by 41%, in GC by 33% and in AM by 50% as compared to the p-CPA with arabic gum treated group. In all groups of animals there occurred neither spontaneous aggressive behavior nor changes in spontaneous motility. The results obtained make it clear that Tween 80 exerts its effect both on biochemical and behavioral processes. Thus, it should be acknowledged that using sorbitans in the investigation of brain mechanisms is inadvisable.

Animals↗
PubMed1990

Immune cells in peripheral lymph and skin of patients with obstructive lymphedema.

Lymph stasis in the extremities caused by interruption of lymphatics or insufficient lymph propulsion is often complicated by recurrent skin infections. To shed further light on this subject, we studied the phenotypical and functional characteristics of cells in peripheral lymph and skin of patients with obstructive lymphedema. Compared with controls, patients with secondary lymphedema displayed a high concentration of lymphocytes and erythrocytes in peripheral lymph, sometimes increased numbers of B cells, increased density of Langerhans cells in the epidermis and occasionally in the skin papillary layer, strong expression of class II antigens on skin endothelial cells and mononuclear infiltration around blood vessels, and margination of granulocytes in skin blood vessels. Reactivity of lymph cells to mitogens was augmented. Taken together these findings indicate that ongoing chronic inflammatory processes persist in skin with lymph stasis, and, moreover, with impaired lymphocyte and Langerhans cell trafficking from skin to regional lymph nodes and inefficient clearance of foreign antigens, these lymphedematous limbs become susceptible to infection.

Antibodies, Monoclonal↗
PubMed1989

Interleukin 2 receptor in rat heart allograft rejection.

Soluble interleukin 2 receptors (S-R-IL-2) of truncated Tac chain, produced in vitro during T lymphocyte activation, may represent an in vivo marker of an alloimmune reaction. We analyzed serum S-R-IL-2 production during acute heart allograft rejection and compared soluble and membranous Tac chain (blood lymphocytes and graft invading cells) regulation during rejection. Serum S-R-IL-2 was tested in an immunoradiometric assay, with a combination of two mouse IgG1 anti-IL2-R mAbs (ART18 and OX39). Membranous Tac chain was analyzed by immunochemistry in graft tissue, and by immunofluorescence on blood and spleen leukocytes. Four experimental groups were used: untreated allogeneic, untreated syngeneic, CsA-treated (10 mg/kg/day for 15 days) allogeneic and CsA-treated syngeneic graft recipients. In the untreated allogeneic group, S-R-IL-2, tested every day until rejection (9.14 +/- 1.6 days), increased as early as day 3 after transplantation, peaked at day 6, and plateaued thereafter. The allograft was infiltrated at day 5 by Tac chain-positive cells (10% of OX1 cells and 84% of OX19 cells). A small percentage of mononucleated cells was labeled in blood, but not in spleen, by ART18 and OX39 at day 7 only. In contrast, in untreated syngeneic and CsA-treated allogeneic combinations, there was no increase of baseline S-R-IL-2 level (P less than 0.001), and graft infiltrate did not contain IL-2-R positive cells. CsA treatment prolonged heart allograft survival (41.3 +/- 2.8 days). Baseline S-R-IL-2 levels during treatment were lower than those observed in untreated animals. In the CsA-treated allogeneic group, after CsA treatment interruption, S-R-IL-2 levels significantly increased, reaching a plateau at day 37. Results suggest that S-R-IL-2 measurement can be useful for clinical diagnosis of allograft rejection.

Animals↗