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1.
BMC Vet Res ; 16(1): 284, 2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778114

RESUMO

BACKGROUND: This is the first report about a vaginal leiomyoma concomitant with an ovarian luteoma in a bitch. CASE PRESENTATION: A 11-year-old intact female Labrador retriever was referred because of anuria, constipation and protrusion of a vaginal mass through the vulvar commissure. The bitch had high serum progesterone concentration (4.94 ng/ml). Because of the possibility of progesterone responsiveness causing further increase of the vaginal mass and since the bitch was a poor surgical candidate a 10 mg/kg aglepristone treatment was started SC on referral day 1. A computerized tomography showed a 12.7 × 6.5 × 8.3 cm mass causing urethral and rectal compression, ureteral dilation and hydronephrosis. A vaginal leiomyoma was diagnosed on histology. As serum progesterone concentration kept increasing despite aglepristone treatment, a 0.02 ng/mL twice daily IM alfaprostol treatment was started on day 18. As neither treatment showed remission of clinical signs or luteolysis, ovariohysterectomy was performed on referral day 35. Multiple corpora lutea were found on both ovaries. On histology a luteoma was diagnosed on the left ovary. P4 levels were undetectable 7 days after surgery. Recovery was uneventful and 12 weeks after surgery tomography showed a reduction of 86.7% of the vaginal mass. The bitch has been in good health and able to urinate without any complication ever since. CONCLUSIONS: This case demonstrates the importance of identifying progesterone related conditions as well as the importance of judiciously using a combined medical and surgical approach.


Assuntos
Doenças do Cão/patologia , Leiomioma/veterinária , Luteoma/veterinária , Progesterona/sangue , Animais , Cães , Estrenos/uso terapêutico , Feminino , Histerectomia/veterinária , Leiomioma/tratamento farmacológico , Leiomioma/cirurgia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/cirurgia , Neoplasias Ovarianas/veterinária , Ovariectomia/veterinária , Progesterona/antagonistas & inibidores , Prostaglandinas F/uso terapêutico , Neoplasias Vaginais/tratamento farmacológico , Neoplasias Vaginais/cirurgia , Neoplasias Vaginais/veterinária
2.
Eur Rev Med Pharmacol Sci ; 23(6): 2669-2680, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30964194

RESUMO

OBJECTIVE: Endothelial dysfunction (ED) predisposes to venous thrombosis (VT) and post-thrombotic syndrome (PTS), a long-term VT-related complication. Sulodexide (SDX) is a highly purified glycosaminoglycan with antithrombotic, pro-fibrinolytic and anti-inflammatory activity used in the treatment of chronic venous disease (CVD), including patients with PTS. SDX has recently obtained clinical evidence in the "extension therapy" after initial-standard anticoagulant treatment for the secondary prevention of recurrent deep vein thrombosis (DVT). Herein, we investigated how SDX counteracts ED. MATERIALS AND METHODS: Human umbilical vein endothelial cells (HUVEC) were used. Metabolic and non metabolic-induced ED was induced by treating with methylglyoxal (MGO) or irradiation (IR), respectively. Bafilomycin A1 was used to inhibit autophagy. The production of reactive oxygen species (ROS), tetrazolium bromide (MTT) assay for cell viability, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay for cell apoptosis, Real-time PCR and Western blot analysis for gene and protein expression were used. RESULTS: SDX protected HUVEC from MGO- or IR-induced apoptosis by counteracting the activation of the intrinsic and extrinsic caspase cascades. The cytoprotective effects of SDX resulted from a reduction in a) ROS production, b) neo-synthesis and release of pro-inflammatory cytokines (TNFα, IL1, IL6, IL8), c) DNA damage induced by MGO or IR. These effects were reduced when autophagy was inhibited. CONCLUSIONS: Data herein collected indicate the ability of SDX to counteract ED induced by metabolic or non-metabolic stresses by involving the intracellular autophagy pathway. Our experience significantly increases the knowledge of the mechanisms of action of SDX against ED and supports the use of SDX in the treatment of CVD, PTS and in the secondary prevention of recurrent DVT.


Assuntos
Glicosaminoglicanos/farmacologia , Células Endoteliais da Veia Umbilical Humana/citologia , Aldeído Pirúvico/efeitos adversos , Raios X/efeitos adversos , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Citocinas/genética , Citocinas/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos da radiação , Humanos , Modelos Biológicos , Espécies Reativas de Oxigênio/metabolismo
3.
Arthritis Res Ther ; 21(1): 39, 2019 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-30696478

RESUMO

BACKGROUND: Autophagy has emerged as a key mechanism in the survival and function of T and B lymphocytes, and its activation was involved in apoptosis resistance in rheumatoid arthritis (RA). To investigate whether the relationship between autophagy and apoptosis may impact the response to the therapy, we analyzed ex vivo spontaneous autophagy and apoptosis in patients with RA subjected to treatment with anti-tumor necrosis factor (TNF) drugs and in vitro the effects of TNFα and anti-TNF drugs on cell fate. METHODS: Peripheral blood mononuclear cells (PBMCs) from 25 RA patients treated with anti-TNF drugs were analyzed for levels of autophagy marker LC3-II by western blot and for the percentage of annexin V-positive apoptotic cells by flow cytometry. The same techniques were used to assess autophagy and apoptosis after in vitro treatment with TNFα and etanercept in both PBMCs and fibroblast-like synoviocytes (FLS) from patients with RA. RESULTS: PBMCs from patients with RA responsive to treatment showed a significant reduction in LC3-II levels, associated with an increased apoptotic activation after 4 months of therapy with anti-TNF drugs. Additionally, the expression of LC3-II correlated with DAS28. TNFα was able to induce autophagy in a dose-dependent manner after 24 h of culture in RA PBMCs and FLS. Moreover, etanercept caused a significant reduction of autophagy and of levels of citrullinated proteins. CONCLUSIONS: Our results show how the crosstalk between autophagy and apoptosis can sustain the survival of immune cells, thus influencing RA progression. This suggests that inhibition of autophagy represents a possible therapeutic target in RA.


Assuntos
Apoptose/efeitos dos fármacos , Artrite Reumatoide/tratamento farmacológico , Autofagia/efeitos dos fármacos , Etanercepte/uso terapêutico , Metotrexato/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Idoso , Antirreumáticos/uso terapêutico , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Células Cultivadas , Etanercepte/metabolismo , Feminino , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Fator de Necrose Tumoral alfa/metabolismo
4.
Cell Tissue Res ; 336(1): 31-40, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19214582

RESUMO

The thyroid-stimulating hormone (TSH) receptor (TSHr) was made specifically fluorescent by insertion of a tetracysteine motif (TSHr-FlAsH) into the C-terminal end and transiently transfected into COS-7 and HeLa cells. The observation that TSH administration caused the intracellular level of cAMP to increase in both TSHr-FlAsH-transfected cell types indicated that the FlAsH binding motif did not alter normal TSHr functioning. When transfected into HeLa cells and stimulated with TSH, the TSHr-FlAsH receptor exhibited a pronounced perinuclear labelling pattern, whereas labelling remained on the cell surface following pre-incubation with 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT). Chinese hamster ovary (CHO)-TSHr cells probed with anti-TSHr antibodies were fluorescent mainly in the proximity of the plasma membrane, with fluorescence being primarily restricted to a juxta-nuclear position when exposed to 10 mU/ml TSH for 1 or 5 min. However, in the presence of DDT, the anti-TSHr fluorescence maintained a peripheral location along the cell plasma membrane, even if CHO-TSHr cells were stimulated with TSH for 1 and 5 min. To verify that DDT acted specifically on the TSHr, CHO cells transfected with the A(2)a receptor were used as controls. Following a 1-min stimulation with 5'-(N-ethyl-carboxamido)-adenosine, A(2)a receptors were gradually internalized regardless of the presence of DDT in the culture medium. Finally, immunoelectron microscopy of CHO-TSHr cells showed that a 1-min exposure to TSH sufficed to displace anti-TSHr antibodies tagged with 10-nm gold particles into coated pits and vesicles but that their superficial location was retained along the plasma membrane in the presence of DDT.


Assuntos
DDT/farmacologia , Disruptores Endócrinos/farmacologia , Receptores da Tireotropina/metabolismo , Glândula Tireoide/efeitos dos fármacos , Animais , Células CHO , Células COS , Chlorocebus aethiops , Cricetinae , Cricetulus , Fluorescência , Células HeLa , Humanos , Transporte Proteico/efeitos dos fármacos , Receptores da Tireotropina/genética , Tireotropina/metabolismo , Tireotropina/farmacologia , Transfecção
5.
Clin Exp Rheumatol ; 26(4): 574-81, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18799087

RESUMO

OBJECTIVE: To verify whether synthetic cannabinoids (CP55,940 and WIN55,212-2) are able to exert an anti-inflammatory effect on rheumatoid fibroblast-like synoviocytes (FLS) by down-regulating cytokine production, and determine whether this effect could be mediated by CB1/CB2 cannabinoid receptors. METHODS: Interleukin-6 (IL-6) and interleukin-8 (IL-8) were assayed in the supernatant from cultured FLS by ELISA method before and after 3 hours of incubation with CP55,940 (10 microM) and WIN55,212-2 (10 microM). Co-stimulation of cells with the cannabinoid receptor antagonists was performed to evaluate receptor involvement in cytokine modulation. All the experiments were conducted in basal conditions and after 1 hour pre-incubation with 0.1 ng/ml IL-1beta. FLS expression of CB1 and CB2 receptor was studied by Western Blot analyses. RESULTS: Both CP55,940 and WIN55,212-2 induced a potent and significant reduction in IL-6 and IL-8 secretion from IL-1beta. stimulated FLS. Although FLS express CB1 and CB2 receptor, cannabinoid receptor antagonists did not significantly modify the inhibition of cytokines secretion induced by CP55,940 and WIN55,212-2. CONCLUSIONS: In vitro, CP55,940 and WIN55,212-2 exert a potent anti-inflammatory effect on rheumatoid FLS via a non-CB1/CB2 receptor mediated mechanism.


Assuntos
Anti-Inflamatórios/farmacologia , Artrite Reumatoide/imunologia , Benzoxazinas/farmacologia , Cicloexanóis/farmacologia , Fibroblastos/efeitos dos fármacos , Morfolinas/farmacologia , Naftalenos/farmacologia , Membrana Sinovial/efeitos dos fármacos , Idoso , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/metabolismo , Estudos de Coortes , Feminino , Fibroblastos/imunologia , Fibroblastos/metabolismo , Humanos , Técnicas In Vitro , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/metabolismo , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Membrana Sinovial/imunologia , Membrana Sinovial/metabolismo
6.
J Biol Chem ; 276(32): 30308-14, 2001 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-11373283

RESUMO

Evidence for heterodimerization has recently been provided for dopamine D(1) and adenosine A(1) receptors as well as for dopamine D(2) and somatostatin SSTR(5) receptors. In this paper, we have studied the possibility that D(2) and D(3) receptors interact functionally by forming receptor heterodimers. Initially, we split the two receptors at the level of the third cytoplasmic loop into two fragments. The first, containing transmembrane domains (TM) I to V and the N-terminal part of the third cytoplasmic loop, was named D(2trunk) or D(3trunk), and the second, containing the C-terminal part of the third cytoplasmic loop, TMVI and TMVII, and the C-terminal tail, was named D(2tail) or D(3tail). Then we defined the pharmacological profiles of the homologous (D(2trunk)/D(2tail) and D(3trunk)/D(3tail)) as well as of the heterologous (D(2trunk)/D(3tail) and D(3trunk)/D(2tail)) cotransfected receptor fragments. The pharmacological profile of the cross-cotransfected fragments was different from that of the native D(2) or D(3) receptors. In most cases, the D(3trunk)/D(2tail) was the one with the highest affinity for most agonists and antagonists. Moreover, we observed that all of these receptor fragments reduced the expression of the wild type dopamine D(2) and D(3) receptors, suggesting that D(2) and D(3) receptors can form complexes with these fragments and that these complexes bind [(3)H]nemonapride less efficiently or are not correctly targeted to the membrane. In a second set of experiments, we tested the ability of the split and the wild type receptors to inhibit adenylyl cyclase (AC) types V and VI. All of the native and split receptors inhibited AC-V and AC-VI, with the exception of D(3), which was unable to inhibit AC-VI. We therefore studied the ability of D(2) and D(3) to interact functionally with one another to inhibit AC-VI. We found that with D(2) alone, R-(+)-7-hydroxydypropylaminotetralin hydrobromide inhibited AC-VI with an IC(50) of 2.05 +/- 0.15 nm, while in the presence of D(2) and D(3) it inhibited AC-VI with an IC(50) of 0.083 +/- 0.011 nm. Similar results were obtained with a chimeric cyclase made from AC-V and AC-VI. Coimmunoprecipitation experiments indicate that D(2) and D(3) receptors are capable of physical interaction.


Assuntos
Receptores de Dopamina D2/química , Adenilil Ciclases/metabolismo , Animais , Células COS , Membrana Celular/metabolismo , Clonagem Molecular , Citoplasma/metabolismo , DNA Complementar/metabolismo , Dimerização , Relação Dose-Resposta a Droga , Immunoblotting , Concentração Inibidora 50 , Testes de Precipitina , Ligação Proteica , Estrutura Terciária de Proteína , Ratos , Receptores de Dopamina D2/fisiologia , Receptores de Dopamina D3 , Transfecção
7.
J Neurochem ; 76(4): 990-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11181818

RESUMO

We have previously shown that systemic injection of (-)nicotine produces a selective up-regulation of fibroblast growth factor (FGF)-2 mRNA levels in rat striatum. Because (-)nicotine can increase striatal release of dopamine and glutamate, in the present study we have investigated the contribution of these neurotransmitters in the modulation of FGF-2 expression. We found that coinjection of dopaminergic D1 (SCH23390) or D2 (haloperidol) receptor antagonists prevents nicotine-induced elevation of FGF-2 expression. However, injection of the NMDA receptor antagonist MK-801 produced a significant increment of FGF-2 mRNA and protein levels in rat striatum similar to the effect produced by (-)nicotine alone. Interestingly this effect of MK-801 could also be prevented by D1 or D2 receptor antagonists, suggesting that an elevation of dopamine levels may be required for the regulation of the trophic molecule. Accordingly we found that the non-selective dopaminergic agonist apomorphine can similarly increase striatal FGF-2 mRNA levels. Despite the observation that both D1 and D2 receptors appear to contribute to the modulation of FGF-2 expression, only a direct activation of D2 receptors, through quinpirole administration, was able to mimic the effect of apomorphine. On the basis of FGF-2 neurotrophic activity, these results suggest that direct or indirect activation of dopaminergic system can be neuroprotective and might reduce cell vulnerability in degenerative disorders.


Assuntos
Corpo Estriado/metabolismo , Dopamina/metabolismo , Fator 2 de Crescimento de Fibroblastos/biossíntese , Animais , Apomorfina/farmacologia , Benzazepinas/farmacologia , Corpo Estriado/efeitos dos fármacos , Maleato de Dizocilpina/farmacologia , Dopamina/farmacologia , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Antagonistas dos Receptores de Dopamina D2 , Antagonistas de Aminoácidos Excitatórios/farmacologia , Fator 2 de Crescimento de Fibroblastos/genética , Haloperidol/farmacologia , Masculino , Nicotina/antagonistas & inibidores , Nicotina/farmacologia , Agonistas Nicotínicos/farmacologia , Quimpirol/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Dopamina D1/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Estereoisomerismo
8.
Eur J Pharmacol ; 433(1): 47-54, 2001 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-11755133

RESUMO

We tested the ability of dopamine, apomorphine, phenylethylamine and pergolide to inhibit the proliferation of fetal calf serum-stimulated human breast cancer (MCF)-7 cells. While the first three compounds were able to block the proliferation of MCF-7 cells, pergolide failed to do so (up to 100 microM). The inhibitory effect of dopamine, apomorphine and phenylethylamine was also evident in serum-starved insulin-stimulated MCF-7 cells. Apomorphine also inhibited the proliferation of the human oestrogen receptor-negative breast cancer (MDA-MB231) and prostate carcinoma (LNCaP) cell lines. In a second set of experiments, we measured the ability of dopamine, apomorphine, phenylethylamine and pergolide to inhibit the phosphorylation (or increase the dephosphorylation) of the insulin receptor substrate (IRS)-1, a major intracellular substrate of the insulin-like growth factor (IGF)-1 receptor. Dopamine, apomorphine and phenylethylamine all reduced to zero the level of phosphorylated IRS-1 with potencies ranging between 0.01 and 1 microM. Finally, we found that fibroblasts from IRS-1 null (-/-) mice were less sensitive to the anti-proliferative effect of apomorphine compared to fibroblasts from wild type-mice, suggesting that the inhibition of IRS-1 phosphorylation by apomorphine is an important aspect of the activity of this compound.


Assuntos
Apomorfina/farmacologia , Dopamina/farmacologia , Fenetilaminas/farmacologia , Fosfoproteínas/metabolismo , Divisão Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Proteínas Substratos do Receptor de Insulina , Pergolida/farmacologia , Fosforilação , Células Tumorais Cultivadas
9.
Eur J Pharmacol ; 397(2-3): 291-6, 2000 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-10844126

RESUMO

An N-terminal dopamine D(2s) receptor clone was constructed and coexpressed in COS-7 cells together with a separate gene fragment coding for the C-terminal sequence of the dopamine D(2s) receptor. The truncated receptor (referred to as D(2trunc)) contained transmembrane domains I-V and the N-terminal portion of the third cytoplasmic loop, whereas the C-terminal receptor fragment (referred to as D(2tail)) contained transmembrane domains VI and VII and the adjacent intra- and extracellular sequences of the dopamine D(2s) receptor. Expression in COS-7 cells of either of these two polypeptides alone did not result in any detectable [3H]methylspiperone binding activity. However, specific [3H]methylspiperone binding could be observed after coexpression of the D(2trunc) and D(2tail) gene constructs; the number of receptors present on the plasma membrane was about 10% with respect to that of the wild type. The binding properties of the coexpressed fragments were similar to those of the wild-type dopamine D(2s) receptor for agonists and antagonists. Functional stimulation of the cotransfected D(2trunc) and D(2tail) fragments with quinpirole resulted in the inhibition of adenylate cyclase activity. Maximal inhibition corresponds to a 28% decrease in forskolin-stimulated adenylate cyclase. The apparent IC(50) of quinpirole was 5.1+/-0.3 mcM. These findings confirm and extend analogous data for other G protein-coupled receptors and indicate that this phenomenon is of general importance for the entire family of these proteins.


Assuntos
Fragmentos de Peptídeos/fisiologia , Receptores de Dopamina D2/fisiologia , Animais , Apomorfina/farmacologia , Ligação Competitiva/efeitos dos fármacos , Células COS , Clozapina/farmacologia , Colforsina/farmacologia , AMP Cíclico/metabolismo , Dopamina/farmacologia , Agonistas de Dopamina/metabolismo , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Relação Dose-Resposta a Droga , Expressão Gênica , Haloperidol/farmacologia , Membranas/metabolismo , Fragmentos de Peptídeos/efeitos dos fármacos , Fragmentos de Peptídeos/genética , Pergolida/farmacologia , Quimpirol/farmacologia , Ensaio Radioligante , Ratos , Receptores de Dopamina D2/efeitos dos fármacos , Receptores de Dopamina D2/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/fisiologia , Espiperona/análogos & derivados , Espiperona/metabolismo , Espiperona/farmacologia , Transfecção , Trítio
10.
Neurotox Res ; 1(4): 285-97, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12835096

RESUMO

Epidemiological studies have shown a reduced incidence of cancer in Parkinson's disease. Since nearly all parkinsonian patients with clinical impairment are treated with L-beta-3,4-dihydroxyphenylalanine (L-DOPA) and dopamine (DA)ergic agonists, a possibility exists that these therapeutic agents can influence the risk of cancer. We studied the antiproliferative effect of these therapeutic agents (and substances structurally correlated) on Chinese hamster ovary (CHO)-K1 cell growth. Among the compounds tested, apomorphine proved to be the most potent inhibitor of CHO-K1 cell growth, with an EC(50) of 3.35 +/- 0.12 micro M. The apomorphine analogues, apocodeine and hydroxyethylnorapomorphine, were less active as inhibitors of CHO-K1 cell growth. The activity of DA, 6-hydroxydopamine (6-OHDA), phenylethylamine (PEA), L-DOPA and bromocriptine as antiproliferative was one order of magnitude lower than that of apomorphine while pergolide was ineffective. To test whether or not the oxidative potential of these compounds was important for their antiproliferative effect, several antioxidants were assayed. Among them glutathione (GSH) and dithiothreitol (DTT) were effective in reversing the anti-proliferative effect of apomorphine, DA, 6-OHDA and PEA, conversely they did not work with bromocriptine. GSH and DTT are sulphydryl-reducing agents; while their effect could explain the efficacy against apomorphine, DA and 6-OHDA, it is difficult to understand why they should have any effect on PEA as this substance does not react with sulphydryl groups. The oxidative potential as a mechanism of action was also questioned by the results obtained with dihydrorhodamine 123, a probe that changes its fluorescent emission wave when oxidized. None of the compounds, with the exception of 6-OHDA, had any effect on the fluorescent emission wave of the probe at the maximal concentrations used to inhibit CHO-K1 cell growth. At concentrations five times higher, apomorphine and DA generated reactive oxygen species but PEA and bromocriptine did not. These data demonstrate that the antiproliferative effect of these compounds is not due to their oxidative potential, but another mechanism must be postulated.

11.
J Neurochem ; 71(6): 2439-46, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9832142

RESUMO

The repeated finding of an apparent protective effect of cigarette smoking on the risk of Parkinson's disease is one of the few consistent results in the epidemiology of this disorder. Among the numerous substances that originate from tobacco smoke, nicotine is by far the most widely studied. Nicotine is a natural alkaloid that has considerable stimulatory effects on the CNS. Its effects on the CNS are mediated by the activation of neuronal heteromeric acetylcholine-gated ion channel receptors (nAChRs, also termed nicotinic acetylcholine receptors). In the present study, we describe the neuroprotective effects of (-)-nicotine in two animal models of parkinsonism: diethyldithiocarbamate-induced enhancement of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity in mice and methamphetamine-induced neurotoxicity in rats and mice. The neuroprotective effect of (-)-nicotine was very similar to that of the noncompetitive NMDA receptor antagonist (+)-MK-801. In parallel experiments, we found that (-)-nicotine induces the basic fibroblast growth factor-2 (FGF-2) and the brain-derived neurotrophic factor in rat striatum. The effect of (-)-nicotine on the induction of FGF-2 was prevented by the nAChR antagonist mecamylamine. We also found that (+)-MK-801 was able to induce FGF-2 in the striatum. As trophic factors have been reported to be neuroprotective for dopaminergic cells, our data suggest that the increase in neurotrophic factors is a possible mechanism by which (-)-nicotine protects from experimental parkinsonisms.


Assuntos
Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Fatores de Crescimento Neural/metabolismo , Nicotina/farmacologia , Doença de Parkinson/prevenção & controle , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Células Cultivadas , Dopamina/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Imuno-Histoquímica , Masculino , Mesencéfalo/citologia , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Tirosina 3-Mono-Oxigenase/metabolismo
12.
J Neural Transm (Vienna) ; 104(10): 1113-23, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9503263

RESUMO

The repeated finding of an apparent protective effect of cigarette smoking on the risk of Parkinson's disease is one of the few consistent results in the epidemiology of this disorder. Among the innumerous substances that originate from tobacco smoke, nicotine is by far the most widely studied, and the most likely candidate for a protective effect against neuronal degeneration in Parkinson's disease. Nicotine is a natural alkaloid that has considerable stimulatory effects on the central nervous system (CNS). Its effects on the CNS are mediated by the activation of neuronal heteromeric acetylcholine-gated ion channel receptors (nAChR, also termed nicotinic acetylcholine receptors). In the present study, we describe the neuroprotective effects of (-)nicotine in two animal models of parkinsonism: the diethyldithiocarbamate (DDC)-induced enhancement of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity in mice, and the methamphetamine-induced neurotoxicity in rats and mice. In parallel experiments, we found that (-)nicotine induces the basic fibroblast growth factor (FGF-2) and the brain-derived neurotrophic factor (BDNF) in rat striatum. As FGF-2 and BDNF have been reported to be neuroprotective for dopaminergic cells, our data indicate that the increase in neurotrophic factors is a possible mechanism by which (-)nicotine protects from experimental parkinsonisms. Moreover, they suggest that nAChR agonists could be of potential benefit in the progression of Parkinson's disease.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator 2 de Crescimento de Fibroblastos/metabolismo , Neostriado/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Nicotina/uso terapêutico , Doença de Parkinson Secundária/tratamento farmacológico , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Animais , Células Cultivadas , Inibidores da Captação de Dopamina , Masculino , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Mesencéfalo/patologia , Metanfetamina , Camundongos , Camundongos Endogâmicos C57BL , Neurotoxinas , Doença de Parkinson Secundária/metabolismo , Doença de Parkinson Secundária/patologia , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Tirosina 3-Mono-Oxigenase/metabolismo
13.
Brain Res ; 741(1-2): 68-74, 1996 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-9001706

RESUMO

L-Deprenyl, a monoamine oxidase (MAO)-B inhibitor, appears to slow down the progression of Parkinson's disease. While inhibition of MAO-B activity can account for some of the effects of this substance, the basis by which L-deprenyl slows the progression of the disease remains controversial. In recent years, a new mechanism of action has emerged that may explain the ability of L-deprenyl to increase neuronal survival. L-deprenyl has been reported to modify gene expression and protein synthesis in astrocytes and PC12 cells. In this study, we tested the ability of L-deprenyl to protect mouse mesencephalic cells from the toxicity of the 1-methyl-4-phenyl pyridinium ion (MPP+). We exposed mouse mesencephalic cell cultures to L-deprenyl (10 microM) and, 24 h later, to MPP+ (2.5 microM). On the fifth day after L-deprenyl and MPP+ exposition, cells were washed free of drugs, and the following day they were tested for dopamine uptake, intracellular dopamine content and tyrosine hydroxylase immunoreactivity. The experiments were performed either in the presence or in the absence of glia. It was found that L-deprenyl pretreatment failed to achieve any protection against MPP+ toxicity. The fall in dopamine uptake and intracellular dopamine content, and the diminution of tyrosine hydroxylase immunoreactivity observed in cells pretreated with L-deprenyl and then given MPP+ were not significantly different from the values observed in cells treated with MPP+ alone. Additional experiments performed in PC12 cells, confirmed the failure of L-deprenyl to abolish the toxicity of MPP+. Our data seem to be at variance with previous reports demonstrating that the MAO-B inhibitor L-deprenyl protects dopaminergic neurons against MPP+ toxicity [12,20]; furthermore they do not support alternative mechanisms of action of L-deprenyl against MPP+ toxicity.


Assuntos
1-Metil-4-fenilpiridínio/toxicidade , Dopaminérgicos/toxicidade , Mesencéfalo/citologia , Inibidores da Monoaminoxidase/farmacologia , Neurônios/efeitos dos fármacos , Selegilina/farmacologia , 1-Metil-4-fenilpiridínio/antagonistas & inibidores , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , Colina/metabolismo , Dopamina/metabolismo , Antagonistas de Dopamina/farmacologia , Imuno-Histoquímica , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Camundongos , Neurônios/metabolismo , Células PC12 , Ratos , Tirosina 3-Mono-Oxigenase/metabolismo
14.
FEBS Lett ; 319(1-2): 195-200, 1993 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8454056

RESUMO

Truncated m2 and m3 muscarinic receptors (referred to as m2- and m3-trunc), containing transmembrane domains I-V and the N-terminal portion of the third cytoplasmic loop, were co-expressed in COS-7 cells with the corresponding C-terminal receptor fragments (referred to as m2- and m3-tail; containing transmembrane domains VI and VII). Expression of any of these four polypeptides alone did not result in any detectable [3H]N-methylscopolamine ([3H]NMS) binding activity. However, specific [3H]NMS binding sites were observed after co-expression of m2-trunc with m2-tail and m3-trunc with m3-tail. These sites displayed ligand binding properties similar to those of the two wild-type receptors. The 'reconstituted' m3-trunc/m3-tail receptor was also able to stimulate agonist-dependent phosphatidyl inositol hydrolysis in a fashion similar to the wild-type m3 receptor, whereas all other polypeptide combinations were inactive. These data suggest that muscarinic receptors are assembled in a fashion analogous to two-subunit receptors.


Assuntos
Fragmentos de Peptídeos/metabolismo , Receptores Muscarínicos/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Expressão Gênica , Humanos , Dados de Sequência Molecular , N-Metilescopolamina , Fragmentos de Peptídeos/genética , Fosfatidilinositóis/metabolismo , Plasmídeos , Conformação Proteica , Ratos , Receptores Muscarínicos/genética , Derivados da Escopolamina/metabolismo , Transfecção
15.
Exp Neurol ; 119(1): 11-9, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8432343

RESUMO

Using in situ hybridization histochemistry for the detection of c-fos mRNA, we examined the pathways activated by seizures evoked by a focal application of bicuculline into a highly discrete epileptogenic site in the deep prepiriform cortex, the area tempestas (AT). Thirty minutes after the initiation of limbic motor seizures evoked by bicuculline in AT, a marked increase in c-fos mRNA was detected in the hippocampal formation, amygdala, olfactory bulb, piriform cortex, and entorhinal cortex. The increase of c-fos mRNA was strictly dependent upon the infusion of the drug in AT. Infusions of bicuculline in the same dose outside the AT did not increase c-fos mRNA levels. The extent to which the mapping pattern of c-fos mRNA expression was specific to limbic seizures was evaluated by examining another focally evoked seizure model involving the application of bicuculline bilaterally into the inferior colliculus. The absence of any detectable c-fos induction in the limbic system after explosive running-bouncing clonic seizures evoked by bicuculline injected into the inferior colliculus indicates that the pattern of activation that we found in the AT-evoked seizure model is not common to all forms of convulsive activity. Furthermore these observations suggest that the pattern of activation we have observed is seizure dependent and not stress induced. Our results indicate that c-fos mRNA expression is useful in the functional mapping of pathways involved in seizure propagation and that the anatomic pattern of activation is selectively related to the type of seizure evoked.


Assuntos
Encéfalo/metabolismo , Condutos Olfatórios/fisiologia , Proteínas Proto-Oncogênicas c-fos/genética , RNA Mensageiro/metabolismo , Convulsões/metabolismo , Animais , Bicuculina/análogos & derivados , Hibridização In Situ , Masculino , Microinjeções , Ratos , Ratos Sprague-Dawley , Convulsões/induzido quimicamente , Distribuição Tecidual
16.
Exp Neurol ; 119(1): 20-31, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8432348

RESUMO

Using in situ hybridization, we previously investigated (17) the regional pattern of c-fos mRNA increases in the brain following convulsive seizures elicited from a highly circumscribed epileptogenic site located in the deep prepiriform cortex. In this paper, we focus on the hippocampus and examine mRNAs encoding other immediate early genes (IEGs), namely c-jun, jun-B, and zif/268, for changes following the focally evoked seizures. Although the anatomic distribution of increases in each IEG mRNA was qualitatively comparable, the temporal analysis indicated that increases in zif/268 mRNA appeared prior to the other genes studied. Each of the mRNAs reached a maximum increase by 30 min and declined to basal levels within 3 h following seizure initiation. The data indicate that these four IEGs respond in a coordinated fashion to propagated seizure activity with increases in mRNA and, furthermore, that increased expression of all four genes appears to occur in the same cell types in the hippocampus.


Assuntos
Encéfalo/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas Imediatamente Precoces , Condutos Olfatórios/fisiologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-jun/genética , RNA Mensageiro/metabolismo , Convulsões/metabolismo , Fatores de Transcrição/genética , Animais , Northern Blotting , Encéfalo/patologia , Proteína 1 de Resposta de Crescimento Precoce , Hibridização In Situ , Masculino , Ratos , Ratos Sprague-Dawley , Tempo de Reação , Convulsões/etiologia , Convulsões/patologia , Distribuição Tecidual
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