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3.133 PERGOLIDE ATTENUATES MEMORY DEFICIENCIES AND OXIDATIVE STRESS INDUCED BY A 6-HYDROXYDOPAMINE MODEL OF PARKINSON'S DISEASE
Wednesday, 14 December 2011 / Parkinsonism and Related Disorders 18S2 (2012) S161–S234
3.131 CONTRIBUTION OF NITRERGIC TRANSMISSION TO THE MODULATION OF L-DOPA ACTIVITY IN THE 6-OHDA MODEL OF PARKINSON’S DISEASE. THERAPEUTIC IMPLICATIONS 1 A. Czarnecka1 , T. Lenda1 , J. Konieczny1 , H. Domin2 , K. Kaminska ´ , 1 1 E. Lorenc-Koci . Department of Neuro-Psychopharmacology, 2 Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland Aim: Our goal was to examine the effects of the nitric oxide donor, molsidomine administered alone or in combination with L-DOPA, on rotational behaviour, brain dopamine metabolism and stereological parameters of the substantia nigra (SN). Methods: Male Wistar rats were injected unilaterally with a single dose of 6-OHDA (8 mg/4 ml) into the left medial forebrain bundle. Only rats exhibiting an extensive loss of nigrostriatal neurons were treated with molsidomine (2 and 4 mg/kg) and L-DOPA (12.5 and 25 mg/kg) alone or in combination, once daily for 14 days. Rotational behaviour was recorded after the first and penultimate doses of the examined drugs. The animals were killed 1 h after the last injections. The level of DA and its metabolites were assayed in striatal and nigral homogenates using an HPLC method. An unbiased stereological technique was used for cell counting throughout the entire SN. Results: Chronic but not acute L-DOPA and molsidomine coadministration resulted predominantly in contralateral rotations whose number was, however, significantly lower than that produced by L-DOPA alone. Moreover, such treatment elevated striatal and nigral level of DA more distinctly than L-DOPA alone. Stereological analysis of nNOS-immunoreactive neurons revealed a 25% decrease in their number in the ipsilateral SN of the 6-OHDAlesioned rats. Chronic L-DOPA treatment led to a significant increase in the total volume of the SN on the lesioned side. Molsidomine prevented the L-DOPA-induced hypertrophy. Conclusion: Our results suggest that combined administration of L-DOPA and a nitric oxide donor may have beneficial effect in the treatment of Parkinson’s disease. 3.132 COMPARISON OF FOUR GDNF-VARIANTS IN THE 6-OHDA RAT MODEL OF PARKINSON’S DISEASE M.H. Piltonen1 , M.M. Bespalov2 , P.T. Mannist ¨ o¨ 1 . 1 Division of Pharmacology and Toxicology, Faculty of Pharmacy, 2 Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland Glial cell line-derived neurotrophic factor (GDNF) enhances the survival, recovery and functionality of dopaminergic neurons in experimental in vitro and in vivo models of Parkinson’s disease. Mature human GDNF is a glycosylated dimer of 134 amino acid (AA) polypeptides, and recombinant human GDNF can be produced in a number of expression systems, including E. coli (resulting in a nonglycosylated protein requiring refolding), baculoviral expression in insect cells, and murine myeloma NSO-cells (producing a glycosylated protein but with an N-terminal truncation of 31 AA). We have also used insect-cell derived GDNF with a 38 AA N-terminal truncation. The GDNF variants were studied in the unilateral 6-OHDA rat model. First the rats received one of the proteins intrastriatally (equimolar doses corresponding to 10 ug of E. coli-GDNF). Six hours later 6-OHDA (2x8 ug) was injected to the same area. When measuring D-amphetamine (2.5 mg/kg)-induced rotations 2–8 weeks post lesion, we observed that the rotational behaviour was attenuated earlier with the truncated variants. At 8 weeks post lesion, however, rotations were similar in all GDNF-treated groups. Surprisingly, there were no differences in dopamine contents of the lesioned striata between control and any GDNF-treated groups at 9 weeks post lesion. Counting of tyrosine hydroxylase (TH)-positive cells in the substantia nigra revealed a small elevation in the cell survival in the GDNF-treated groups. However, there were large
S197
areas in many samples on the intact side of the substantia nigra where TH-cells could not be detected, which may skew the result. 3.133 PERGOLIDE ATTENUATES MEMORY DEFICIENCIES AND OXIDATIVE STRESS INDUCED BY A 6-HYDROXYDOPAMINE MODEL OF PARKINSON’S DISEASE M. Padurariu1 , L. Hritcu2 , A. Ciobica2 , A. Neagu2 . 1 Gr. T. Popa University of Medicine and Pharmacy Iasi, 2 Alexandru Ioan Cuza University, Iasi, Romania Introduction: One of the most widely used animal models of Parkinson’s disease (PD) involve injecting of 6-hydroxydopamine (6-OHDA) directly into the substantia nigra (SN) and results in cognitive deficiencies and increase oxidative stress. Dopaminergic drugs may exert brain antioxidant activity which could explain their protective actions. The aim of this study was to examine the effects of pergolide on behavioral deficits and brain oxidative stress induced by 6-OHDA in this rat model of PD. Methods: 8 mg 6-OHDA dissolved in 4 ml saline was administrated. Two weeks after operation, all surviving animals showing no neurological abnormalities were admitted to pergolide treatment (0.3 mg/kg/day i.p.). Radial-8-arm-maze and Y-maze tasks were used. We also assessed the levels of some enzymatic antioxidant defences like superoxide dismutase (SOD) and glutathione peroxidase (GPX), as well as lipid oxidation makers like MDA (malondialdehyde), from the temporal lobe. Results: We observed a significant facilitation of pergolide in Y-maze task and a decrease in the number of working and reference memory errors from the radial-arm-maze, suggesting significant positive effects on spatial memory. Additionally, an increase in the specific activity of SOD and GPX was noticed in pergolide-treated rats, compared to control group. Moreover, Pearson’s test revealed a significant positive correlation between spontaneous alternation in Y-maze and SOD specific activity. Conclusions: Taken together, our data suggest that pergolide may counteract both behavioral and biochemical changes induced by 6-OHDA in a rat model of PD. Our study also suggests that these positive behavioral responses could be correlated with some antioxidant actions of pergolide. 3.134 NEUROCHEMICAL AND BEHAVIORAL CHANGES CORRESPONDING TO THE ADVANCED PARKINSON’S DISEASE WITH COEXISTENT DEPRESSION IN RATS TREATED UNILATERALLY WITH 6-OHDA E. Lorenc-Koci, T. Lenda, K. Kaminska, ´ A. Czarnecka, J. Konieczny. Department of Neuro-Psychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland Parkinson’s disease (PD) is characterized by major motor deficits (bradykinesia, rigidity, postural instability) and more than 40% incidence of depression. The aim of our study was to establish an animal model of PD corresponding to the advanced stage of the disease with coexisting depressive symptoms. Experiments were performed on male Wistar rats injected unilaterally with a single dose of 6-OHDA (8 mg/4 ml, 12 mg/4 ml or 16 mg/4 ml), with or without desipramine (25 mg/kg), into the left medial forebrain bundle. The sucrose preference test, as a measure of anhedonia, was performed several times before and after surgery. Four weeks after 6-OHDA administration rats were sacrificed and the levels of dopamine (DA), noradrenaline (NA) and serotonin (5-HT) were determined in the isolated brain structures: prefrontal cortex (PFC), hippocampus (HIP), striatum (STR) and substantia nigra (SN) using an HPLC method. Preference for sucrose consumption was most strongly reduced in rats injected with 16 mg/4 ml of 6-OHDA. All doses of 6-OHDA produced significant declines in DA levels in all ipsilateral structures
3.131 CONTRIBUTION OF NITRERGIC TRANSMISSION TO THE MODULATION OF L-DOPA ACTIVITY IN THE 6-OHDA MODEL OF PARKINSON’S DISEASE. THERAPEUTIC IMPLICATIONS 1 A. Czarnecka1 , T. Lenda1 , J. Konieczny1 , H. Domin2 , K. Kaminska ´ , 1 1 E. Lorenc-Koci . Department of Neuro-Psychopharmacology, 2 Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland Aim: Our goal was to examine the effects of the nitric oxide donor, molsidomine administered alone or in combination with L-DOPA, on rotational behaviour, brain dopamine metabolism and stereological parameters of the substantia nigra (SN). Methods: Male Wistar rats were injected unilaterally with a single dose of 6-OHDA (8 mg/4 ml) into the left medial forebrain bundle. Only rats exhibiting an extensive loss of nigrostriatal neurons were treated with molsidomine (2 and 4 mg/kg) and L-DOPA (12.5 and 25 mg/kg) alone or in combination, once daily for 14 days. Rotational behaviour was recorded after the first and penultimate doses of the examined drugs. The animals were killed 1 h after the last injections. The level of DA and its metabolites were assayed in striatal and nigral homogenates using an HPLC method. An unbiased stereological technique was used for cell counting throughout the entire SN. Results: Chronic but not acute L-DOPA and molsidomine coadministration resulted predominantly in contralateral rotations whose number was, however, significantly lower than that produced by L-DOPA alone. Moreover, such treatment elevated striatal and nigral level of DA more distinctly than L-DOPA alone. Stereological analysis of nNOS-immunoreactive neurons revealed a 25% decrease in their number in the ipsilateral SN of the 6-OHDAlesioned rats. Chronic L-DOPA treatment led to a significant increase in the total volume of the SN on the lesioned side. Molsidomine prevented the L-DOPA-induced hypertrophy. Conclusion: Our results suggest that combined administration of L-DOPA and a nitric oxide donor may have beneficial effect in the treatment of Parkinson’s disease. 3.132 COMPARISON OF FOUR GDNF-VARIANTS IN THE 6-OHDA RAT MODEL OF PARKINSON’S DISEASE M.H. Piltonen1 , M.M. Bespalov2 , P.T. Mannist ¨ o¨ 1 . 1 Division of Pharmacology and Toxicology, Faculty of Pharmacy, 2 Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland Glial cell line-derived neurotrophic factor (GDNF) enhances the survival, recovery and functionality of dopaminergic neurons in experimental in vitro and in vivo models of Parkinson’s disease. Mature human GDNF is a glycosylated dimer of 134 amino acid (AA) polypeptides, and recombinant human GDNF can be produced in a number of expression systems, including E. coli (resulting in a nonglycosylated protein requiring refolding), baculoviral expression in insect cells, and murine myeloma NSO-cells (producing a glycosylated protein but with an N-terminal truncation of 31 AA). We have also used insect-cell derived GDNF with a 38 AA N-terminal truncation. The GDNF variants were studied in the unilateral 6-OHDA rat model. First the rats received one of the proteins intrastriatally (equimolar doses corresponding to 10 ug of E. coli-GDNF). Six hours later 6-OHDA (2x8 ug) was injected to the same area. When measuring D-amphetamine (2.5 mg/kg)-induced rotations 2–8 weeks post lesion, we observed that the rotational behaviour was attenuated earlier with the truncated variants. At 8 weeks post lesion, however, rotations were similar in all GDNF-treated groups. Surprisingly, there were no differences in dopamine contents of the lesioned striata between control and any GDNF-treated groups at 9 weeks post lesion. Counting of tyrosine hydroxylase (TH)-positive cells in the substantia nigra revealed a small elevation in the cell survival in the GDNF-treated groups. However, there were large
S197
areas in many samples on the intact side of the substantia nigra where TH-cells could not be detected, which may skew the result. 3.133 PERGOLIDE ATTENUATES MEMORY DEFICIENCIES AND OXIDATIVE STRESS INDUCED BY A 6-HYDROXYDOPAMINE MODEL OF PARKINSON’S DISEASE M. Padurariu1 , L. Hritcu2 , A. Ciobica2 , A. Neagu2 . 1 Gr. T. Popa University of Medicine and Pharmacy Iasi, 2 Alexandru Ioan Cuza University, Iasi, Romania Introduction: One of the most widely used animal models of Parkinson’s disease (PD) involve injecting of 6-hydroxydopamine (6-OHDA) directly into the substantia nigra (SN) and results in cognitive deficiencies and increase oxidative stress. Dopaminergic drugs may exert brain antioxidant activity which could explain their protective actions. The aim of this study was to examine the effects of pergolide on behavioral deficits and brain oxidative stress induced by 6-OHDA in this rat model of PD. Methods: 8 mg 6-OHDA dissolved in 4 ml saline was administrated. Two weeks after operation, all surviving animals showing no neurological abnormalities were admitted to pergolide treatment (0.3 mg/kg/day i.p.). Radial-8-arm-maze and Y-maze tasks were used. We also assessed the levels of some enzymatic antioxidant defences like superoxide dismutase (SOD) and glutathione peroxidase (GPX), as well as lipid oxidation makers like MDA (malondialdehyde), from the temporal lobe. Results: We observed a significant facilitation of pergolide in Y-maze task and a decrease in the number of working and reference memory errors from the radial-arm-maze, suggesting significant positive effects on spatial memory. Additionally, an increase in the specific activity of SOD and GPX was noticed in pergolide-treated rats, compared to control group. Moreover, Pearson’s test revealed a significant positive correlation between spontaneous alternation in Y-maze and SOD specific activity. Conclusions: Taken together, our data suggest that pergolide may counteract both behavioral and biochemical changes induced by 6-OHDA in a rat model of PD. Our study also suggests that these positive behavioral responses could be correlated with some antioxidant actions of pergolide. 3.134 NEUROCHEMICAL AND BEHAVIORAL CHANGES CORRESPONDING TO THE ADVANCED PARKINSON’S DISEASE WITH COEXISTENT DEPRESSION IN RATS TREATED UNILATERALLY WITH 6-OHDA E. Lorenc-Koci, T. Lenda, K. Kaminska, ´ A. Czarnecka, J. Konieczny. Department of Neuro-Psychopharmacology, Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland Parkinson’s disease (PD) is characterized by major motor deficits (bradykinesia, rigidity, postural instability) and more than 40% incidence of depression. The aim of our study was to establish an animal model of PD corresponding to the advanced stage of the disease with coexisting depressive symptoms. Experiments were performed on male Wistar rats injected unilaterally with a single dose of 6-OHDA (8 mg/4 ml, 12 mg/4 ml or 16 mg/4 ml), with or without desipramine (25 mg/kg), into the left medial forebrain bundle. The sucrose preference test, as a measure of anhedonia, was performed several times before and after surgery. Four weeks after 6-OHDA administration rats were sacrificed and the levels of dopamine (DA), noradrenaline (NA) and serotonin (5-HT) were determined in the isolated brain structures: prefrontal cortex (PFC), hippocampus (HIP), striatum (STR) and substantia nigra (SN) using an HPLC method. Preference for sucrose consumption was most strongly reduced in rats injected with 16 mg/4 ml of 6-OHDA. All doses of 6-OHDA produced significant declines in DA levels in all ipsilateral structures