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1.
J Neurochem ; 149(5): 605-623, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30968952

RESUMO

Regulation of neurotransmitter release in the central nervous system is complex. Here, we investigated regulatory mechanisms for acetylcholine (ACh) release from cholinergic neurons by performing superfusion experiments with rat striatal segments after labelling the cellular ACh pool with [3 H]choline. Electrical stimulation-evoked pronounced [3 H]ACh release from cholinergic neurons. The estimated quantity of [3 H]ACh release per pulse of electrical stimulation was reduced by an increase in stimulus frequency, showing an inverse correlation between release probability of ACh and neuronal excitation. ACh release was also negatively regulated by pre-synaptic muscarinic ACh receptors (mAChRs). The autoinhibition induced by released ACh was predominantly suppressed by the M2 -selective antagonist AF-DX 116, partially inhibited by M3 -selective darifenacin, and minimally by M4 -selective PD 102807. Other subtype-selective antagonists had no effect at subtype-selective concentrations. ACh esterase (AChE) inhibitors (diisopropylfluorophosphate, donepezil and galantamine) at concentrations that mostly inhibit esterase activity reduced [3 H]ACh release, and the reduction was abolished by treatment with atropine. This implies that pre-synaptic autoreceptors are activated more after blockade of ACh hydrolysis, leading to autoinhibition of ACh release and consequent reduction in synaptic ACh concentrations. [3 H]efflux was also enhanced by ACh uptake inhibitors (100 µM hemicholinium-3 and physostigmine), regardless of ACh hydrolysis. This study shows that synaptic ACh concentrations in striatal cholinergic neurons are regulated in a complex manner by many factors such as release probability, pre-synaptic M2 /M3 /M4 mAChRs, AChE and post-synaptic ACh uptake, and provides important information about cholinergic neurotransmission for future exploration of therapeutic strategies for Alzheimer's and other central nervous system diseases. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/openscience-badges/.


Assuntos
Acetilcolina/metabolismo , Neurônios Colinérgicos/efeitos dos fármacos , Neurônios Colinérgicos/metabolismo , Inibidores da Colinesterase/farmacologia , Antagonistas Muscarínicos/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Animais , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Masculino , Ratos , Ratos Wistar , Receptores Muscarínicos/metabolismo , Transmissão Sináptica/fisiologia
2.
J Neurochem ; 143(1): 76-86, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28700094

RESUMO

In addition to hydrolysis by acetylcholine esterase (AChE), acetylcholine (ACh) is also directly taken up into brain tissues. In this study, we examined whether the uptake of ACh is involved in the regulation of synaptic ACh concentrations. Superfusion experiments with rat striatal segments pre-incubated with [3 H]choline were performed using an ultra-mini superfusion vessel, which was developed to minimize superfusate retention within the vessel. Hemicholinium-3 (HC-3) at concentrations less than 1 µM, selectively inhibited the uptake of [3 H]choline by the high affinity-choline transporter 1 and had no effect on basal and electrically evoked [3 H]efflux in superfusion experiments. In contrast, HC-3 at higher concentrations, as well as tetraethylammonium (>10 µM), which inhibited the uptake of both [3 H]choline and [3 H]ACh, increased basal [3 H]overflow and potentiated electrically evoked [3 H]efflux. These effects of HC-3 and tetraethylammonium were also observed under conditions where tissue AChE was irreversibly inactivated by diisopropylfluorophosphate. Specifically, the potentiation of evoked [3 H]efflux was significantly higher in AChE-inactivated preparations and was attenuated by atropine. On the other hand, striatal segments pre-incubated with [3 H]ACh failed to increase [3 H]overflow in response to electrical stimulation. These results show that synaptic ACh concentrations are significantly regulated by the postsynaptic uptake of ACh, as well as by AChE hydrolysis and modulation of ACh release mediated through presynaptic muscarinic ACh receptors. In addition, these data suggest that the recycling of ACh-derived choline may be minor in cholinergic terminals. This study reveals a new mechanism of cholinergic transmission in the central nervous system.


Assuntos
Acetilcolina/metabolismo , Neurônios Colinérgicos/metabolismo , Corpo Estriado/metabolismo , Terminações Pré-Sinápticas/metabolismo , Sinapses/metabolismo , Transmissão Sináptica/fisiologia , Animais , Transporte Biológico/fisiologia , Colina/metabolismo , Hemicolínio 3/metabolismo , Masculino , Técnicas de Cultura de Órgãos/métodos , Ratos , Ratos Wistar
3.
Drug Des Devel Ther ; 10: 2669-76, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27578964

RESUMO

BACKGROUND: G-protein-coupled bile acid receptor 1, also known as TGR5 is known to be involved in glucose homeostasis. In animal models, treatment with a TGR5 agonist induces incretin secretion to reduce hyperglycemia. Betulinic acid, a triterpenoid present in the leaves of white birch, has been introduced as a selective TGR5 agonist. However, direct activation of TGR5 by betulinic acid has not yet been reported. METHODS: Transfection of TGR5 into cultured Chinese hamster ovary (CHO-K1) cells was performed to establish the presence of TGR5. Additionally, TGR5-specific small interfering RNA was employed to silence TGR5 in cells (NCI-H716 cells) that secreted incretins. Uptake of glucose by CHO-K1 cells was evaluated using a fluorescent indicator. Amounts of cyclic adenosine monophosphate and glucagon-like peptide were quantified using enzyme-linked immunosorbent assay kits. RESULTS: Betulinic acid dose-dependently increases glucose uptake by CHO-K1 cells transfected with TGR5 only, which can be considered an alternative method instead of radioligand binding assay. Additionally, signals coupled to TGR5 activation are also increased by betulinic acid in cells transfected with TGR5. In NCI-H716 cells, which endogenously express TGR5, betulinic acid induces glucagon-like peptide secretion via increasing calcium levels. However, the actions of betulinic acid were markedly reduced in NCI-H716 cells that received TGR5-silencing treatment. Therefore, the present study demonstrates the activation of TGR5 by betulinic acid for the first time. CONCLUSION: Similar to the positive control lithocholic acid, which is the established agonist of TGR5, betulinic acid has been characterized as a useful agonist of TGR5 and can be used to activate TGR5 in the future.


Assuntos
Receptores Acoplados a Proteínas G/agonistas , Triterpenos/farmacologia , Animais , Células CHO , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Humanos , Triterpenos Pentacíclicos , Relação Estrutura-Atividade , Triterpenos/síntese química , Triterpenos/química , Células Tumorais Cultivadas , Ácido Betulínico
4.
Naunyn Schmiedebergs Arch Pharmacol ; 389(11): 1215-1223, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27485449

RESUMO

Amarogentin is a bitter-tasting secoiridoid glycoside isolated from an herb. Inhibition of aldose reductase by amarogentin has been documented as an antidiabetic action. However, the mechanisms of action of amarogentin in diabetic disorders remain unknown. The present study employed streptozotocin-induced type 1 diabetic (T1DM) rats to investigate the antihyperglycemic action of amarogentin. Changes in the protein expression of glucose transporter 4 (GLUT4) and phosphoenolpyruvate carboxykinase (PEPCK) in skeletal muscle and liver, respectively, were also detected by Western blotting. Additionally, a type 2 diabetes (T2DM) animal model induced using a fructose-rich diet was also applied to assess the effect of amarogentin on insulin resistance according to the homeostasis model assessment-insulin resistance (HOMA-IR). Amarogentin dose-dependently attenuated hyperglycemia in the T1DM rats lacking insulin. The action of amarogentin was further supported in rats administered the oral glucose tolerance test. Western blotting showed that amarogentin reversed the decreased GLUT4 level in skeletal muscle and reduced the elevated PEPCK expression in livers isolated from the T1DM rats. Moreover, amarogentin decreased the HOMA-IR and increased insulin sensitivity in the T2DM rats. These data show that amarogentin may ameliorate glucose homeostasis in diabetic rats, indicating its potential for future development as an antidiabetic drug.


Assuntos
Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Iridoides/farmacologia , Animais , Biomarcadores/sangue , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 1/enzimologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/etiologia , Carboidratos da Dieta , Relação Dose-Resposta a Droga , Frutose , Teste de Tolerância a Glucose , Transportador de Glucose Tipo 4/metabolismo , Insulina/sangue , Resistência à Insulina , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/enzimologia , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Ratos Wistar , Estreptozocina
5.
Drug Des Devel Ther ; 10: 1877-84, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27350742

RESUMO

BACKGROUND: Erythropoietin (EPO) is widely used in diabetic patients receiving hemodialysis. The role of EPO in glucose homeostasis remains unclear. Therefore, we investigated the effect of EPO on hyperglycemia in rats with type 1-like diabetes. METHODS: Rats with streptozotocin-induced type 1-like diabetes (STZ rats) were used to estimate the blood glucose-lowering effects of EPO, and changes in the expression levels of glucose transporter 4 (GLUT4) and the hepatic enzyme phosphoenolpyruvate carboxykinase (PEPCK) were identified by Western blot analysis. RESULTS: EPO attenuated the hyperglycemia in the STZ rats in a dose-dependent manner without altering the hematopoietic parameters, including the hematocrit and number of red blood cells. The involvement of the EPO receptor (EPOR) was identified using EPOR-specific antibodies. In addition, injection of EPO enhanced the glucose utilization, which was assessed using an intravenous glucose tolerance test in rats. However, blood insulin was not changed by EPO in this assay, showing the insulinotropic action of EPO. Moreover, EPO treatment increased the insulin sensitivity. Western blots indicated that the phosphorylation of AMP-activated protein kinase was enhanced by EPO to support the signaling caused by EPOR activation. Furthermore, the decrease in the GLUT4 level in skeletal muscle was reversed by EPO, and the increase in the PEPCK expression in liver was reduced by EPO, as shown in STZ rats. CONCLUSION: Taken together, the results show that EPO injection may reduce hyperglycemia in diabetic rats through activation of EPO receptors. Therefore, EPO is useful for managing diabetic disorders, particularly hyperglycemia-associated changes. In addition, EPO receptor will be a good target for the development of antihyperglycemic agent(s) in the future.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Eritropoetina/uso terapêutico , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/induzido quimicamente , Modelos Animais de Doenças , Eritropoetina/administração & dosagem , Hiperglicemia/induzido quimicamente , Hipoglicemiantes/administração & dosagem , Insulina/sangue , Masculino , Ratos , Ratos Wistar , Estreptozocina
6.
Drug Des Devel Ther ; 9: 5625-32, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26508837

RESUMO

BACKGROUND: The development of new drugs for the treatment of diabetes mellitus (DM) is critically important. Insulin resistance (IR) is one of the main problems associated with type-2 DM (T2DM) seen in clinics. GW0742, a selective peroxisome proliferator-activated receptor (PPAR)-δ agonist, has been shown to ameliorate metabolic abnormalities including IR in skeletal muscle in mice fed high-fructose corn syrup. However, the influence of GW0742 on systemic insulin sensitivity has still not been elucidated. Therefore, it is important to investigate the effect of GW0742 on systemic IR in diabetic rats for the development of new drugs. METHODS: The present study used a T2DM animal model to compare the effect of GW0742 on IR using homeostasis model assessment-IR (HOMA-IR) and hyperinsulinemic euglycemic clamping. Additionally, the insulinotropic action of GW0742 was investigated in type-1 DM (T1DM) rats. Changes in the protein expression of glucose transporter 4 (GLUT4) and phosphoenolpyruvate carboxykinase (PEPCK) in skeletal muscle and in liver, respectively, were also identified by Western blots. RESULTS: GW0742 attenuated the increased HOMA-IR in diabetic rats fed a fructose-rich diet. This action was blocked by GSK0660 at the dose sufficient to inhibit PPAR-δ. Improvement of IR by GW0742 was also characterized in diabetic rats using hyperinsulinemic euglycemic clamping. Additionally, an increase of insulin sensitivity due to GW0742 was observed in these diabetic rats. Moreover, GW0742 reduced the hyperglycemia in T1DM rats lacking insulin. Western blotting analysis indicated that GW0742 reversed the decrease in GLUT4 and markedly reduced the increased PEPCK in liver. CONCLUSION: The data showed that GW0742 has the ability to improve glucose homeostasis in diabetic rats through activation of PPAR-δ. Therefore, PPAR-δ is a good target for the development of antidiabetic drugs in the future.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Descoberta de Drogas/métodos , Hipoglicemiantes/farmacologia , PPAR alfa/agonistas , Tiazóis/farmacologia , Animais , Biomarcadores/sangue , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/induzido quimicamente , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/etiologia , Relação Dose-Resposta a Droga , Frutose , Transportador de Glucose Tipo 4/metabolismo , Homeostase , Insulina/sangue , Resistência à Insulina , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , PPAR alfa/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Ratos Wistar , Estreptozocina , Fatores de Tempo
7.
BMC Complement Altern Med ; 15: 70, 2015 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-25886358

RESUMO

BACKGROUND: The antinociceptive effect of an aqueous extract from the leaves of Toona sinensis (TS, [A. Juss., M. Roem.]) was studied using the writhing test in mice. METHODS: Different extraction fractions from TS leaf extracts (TSL1 to TSL5) were administered orally 1 h before intraperitoneal injection of acetic acid. RESULTS: After treatment with TSL1, TSL2, TSL3, TSL4, and TSL5 at a dose of 1 g/kg, the respective writhing responses were 39.9% (P < 0.001), 19.9% (P < 0.05), 11.7% (P = 0.052), 8.1% (P = 0.188), and 11.4% (P = 0.057) lower than the control group. Mice treated with TSL1 at 1 g/kg (39.9%, P < 0.001), 0.3 g/kg (38.0%, P < 0.001), 0.1 g/kg (46.9%, P < 0.001), and 0.03 g/kg (31.1%, P < 0.001) had significantly lower writhing responses compared with control mice. A time-course experiment was performed, which involved oral administration of TSL1 (0.1 g/kg) at 0, 0.5, 1, 2, and 6 h before acetic acid intraperitoneal injection. The most effective dose of TSL1 was 0.1 g/kg orally, with the effect beginning 30 min before treatment and persisting until 6 h. CONCLUSIONS: This study showed that TS has anti-visceral pain properties comparable with those of rofecoxib (a cyclooxygenase-2 inhibitor) and diclofenac, which suggests promise for the treatment of intractable visceral pain in humans.


Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios não Esteroides/uso terapêutico , Meliaceae , Dor/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Ácido Acético , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Comportamento Animal/efeitos dos fármacos , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Diclofenaco/farmacologia , Diclofenaco/uso terapêutico , Humanos , Lactonas/farmacologia , Lactonas/uso terapêutico , Masculino , Camundongos Endogâmicos ICR , Dor/induzido quimicamente , Extratos Vegetais/farmacologia , Folhas de Planta/efeitos dos fármacos , Sulfonas/farmacologia , Sulfonas/uso terapêutico
8.
PPAR Res ; 2014: 456386, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24817882

RESUMO

Changes in the peroxisome proliferator-activated receptors- δ (PPAR δ ) expression in rats after spinal cord injury (SCI) have been previously reported. Diabetic animals show a higher mortality after SCI. However, the relationship between the progress of diabetes and PPAR δ in SCI remains unknown. In the present study, we used compressive SCI in streptozotocin-(STZ-) induced diabetic rats. GW0742, a PPAR δ agonist, was used to evaluate its merit in STZ rats after SCI. Changes in PPAR δ expression were detected by Western blot. Survival rates were also estimated. A lower expression of PPAR δ in spinal cords of STZ-diabetic rats was observed. In addition, the survival times in two-week induction diabetes were longer than those in eight-week induction group, which is consistent with the expression of PPAR δ in the spinal cord. Moreover, GW0742 significantly increased the survival time of STZ rats. Furthermore, their motor function and pain response were attenuated by GSK0660, a selective PPAR δ antagonist, but were enhanced by GW0742. In conclusion, the data suggest that higher mortality rate in STZ-diabetic rats with SCI is associated with the decrease of PPAR δ expression. Thus, change of PPAR δ expression with the progress of diabetes seems responsible for the higher mortality rate after SCI.

9.
PLoS One ; 8(5): e64229, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23724037

RESUMO

BACKGROUND AND AIMS: Agents having a positive inotropic effect on the heart are widely used for the treatment of heart failure. However, these agents have the side effect of altering heart rate. It has been established that peroxisome proliferator-activated receptor δ (PPARδ) is mediated in cardiac contraction, however the effect on heart rate is unknown. Thus, we used an agonist of PPARδ, GW0742, to investigate this issue in the present study. METHODS AND RESULTS: We used isolated hearts in Langendorff apparatus and hemodynamic analysis in catheterized rats to measure the actions of GW0742 extra-vivo and in vivo. In diabetic rats with heart failure, GW0742 at a dose sufficient to activate PPARδ reversed cardiac contraction without changes in heart rate. In normal rats, PPARδ enhanced cardiac contractility and hemodynamic dP/dtmax significantly more than dobutamine. Both actions were diminished by GSK0660 at a dose enough to block PPARδ. However, GW0742 at the same dose failed to modify heart rate, although it did produce a mild increase in blood pressure. Detection of intracellular calcium level and Western blotting analysis showed that the intracellular calcium concentration and troponin I phosphorylation were both enhanced by GW0742. CONCLUSION: Activation of PPARδ by GW0742 increases cardiac contractility but not heart rate. Thus, PPARδ may be a suitable target for the development of inotropic agents to treat heart failure without changing heart rate.


Assuntos
Contração Miocárdica , Miocárdio/metabolismo , PPAR delta/metabolismo , Anestesia , Animais , Animais Recém-Nascidos , Pressão Sanguínea/efeitos dos fármacos , Cálcio/metabolismo , Diabetes Mellitus Experimental/diagnóstico por imagem , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/fisiopatologia , Dobutamina/farmacologia , Relação Dose-Resposta a Droga , Frequência Cardíaca/efeitos dos fármacos , Técnicas In Vitro , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Masculino , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fosforilação/efeitos dos fármacos , Ratos , Ratos Wistar , Estreptozocina , Tiazóis/farmacologia , Troponina I/metabolismo , Ultrassonografia
10.
Auton Neurosci ; 177(2): 211-6, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23701913

RESUMO

BACKGROUND: Role of peroxisome proliferator-activated receptor δ (PPARδ) in cardiac contraction has recently been established. Dopamine is one of the agents used to treat heart failure in clinics. But the mediation of PPARδ in cardiac action of dopamine is still unclear. METHODS: The present study is aimed to clarify this point using neonatal rat cardiomyocytes to investigate the changes of PPARδ expression and cardiac troponin I (cTnI) phosphorylation by Western blotting analysis. Antagonists of receptors, inhibitor of phospholipase C (PLC) (U73122), calcium chelator (BAPTA-AM), and inhibitor of protein kinase A (PKAI) were also applied. We silenced PPARδ by RNAi to identify the major role of PPARδ in dopamine-induced actions. RESULTS: Dopamine increases PPARδ expression and cardiac troponin I (cTnI) phosphorylation in a time- and dose-dependent manner in neonatal rat cardiomyocytes. Moreover, both actions of dopamine were blocked by DA1 receptor antagonist and PLC inhibitor but not by PKAI. The increase of cTnI phosphorylation by dopamine was also inhibited in cardiomyocytes silenced by RNAi of PPARδ. CONCLUSION: We suggest that dopamine can enhance cardiac contraction mainly through an activation of DA1 receptor-linked PLC pathway to increase cellular calcium ions for the increase of PPARδ expression.


Assuntos
Dopamina/fisiologia , Miócitos Cardíacos/metabolismo , PPAR delta/biossíntese , Receptores de Dopamina D1/metabolismo , Transdução de Sinais/fisiologia , Fosfolipases Tipo C/metabolismo , Animais , Animais Recém-Nascidos , Células Cultivadas , Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Inibidores Enzimáticos/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Ratos Wistar , Receptores de Dopamina D1/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Fosfolipases Tipo C/antagonistas & inibidores
11.
Artigo em Inglês | MEDLINE | ID: mdl-23606885

RESUMO

The activation of the imidazoline I1-receptor (I1R) is known to regulate appetite. Allantoin, an active ingredient in the yam, has been reported to improve lipid metabolism in high fat diet- (HFD-)fed mice. However, the effect of allantoin on obesity remains unclear. In the present study, we investigated the effects of allantoin on HFD-induced obesity. The chronic administration of allantoin to HFD-fed mice for 8 weeks significantly decreased their body weight, and this effect was reversed by efaroxan at a dose sufficient to block I1R. The epididymal white adipose tissue (eWAT) cell size and weight in HFD-fed mice were also decreased by allantoin via the activation of I1R. In addition, allantoin significantly decreased the energy intake of HFD-fed mice, and this reduction was associated with a decrease in the NPY levels in the brain. However, no inhibitory effect of allantoin on energy intake was observed in db/db mice. Moreover, allantoin lowered HFD-induced hyperleptinemia, and this activity was abolished by I1R blockade with efaroxan. Taken together, these data suggest that allantoin can ameliorate energy intake and eWAT accumulation by activating I1R to improve HFD-induced obesity.

12.
Cytokine ; 61(2): 413-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23260996

RESUMO

Transforming growth factor-beta 1 (TGF-ß1) has been reported to be a possible marker for a number of tumors, including brain tumors. The aim of this study was to measure the plasma levels of TGF-ß1 in patients with low- and high-grade astrocytomas before and after surgery. This prospective study included 14 patients with low-grade astrocytomas and 25 with high-grade astrocytomas who underwent tumor removal and 13 controls (patients who underwent cranioplasty for skull bone defects). Plasma levels of TGF-ß1 were measured in all subjects using enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve analysis showed that when the level of TGF-ß1 before tumor removal was ≥ 2.52 ng/ml, astrocytoma was predicted with a sensitivity of 94.9% and specificity of 100%. The mean plasma level of TGF-ß1 in both the low-grade and high-grade astrocytoma groups significantly decreased after tumor removal (p<0.05); there was no significant change in TGF-ß1 plasma level of the controls following surgery. Patients with high-grade astrocytomas had a significantly higher mortality rate than patients with low-grade astrocytomas (p=0.019) and significantly shorter survival (p=0.008). A positive correlation between TGF-ß1 level after tumor removal and tumor volume was only found in the high-grade astrocytoma group (γ=0.597, p=0.002). The findings show that plasma TGF-ß1 level was increased in patients with low-grade and high-grade astrocytoma, and that the levels significantly decreased after tumor removal in both groups. The results provide additional evidence that TGF-ß1 might be useful as a tumor marker for astrocytomas.


Assuntos
Astrocitoma/sangue , Astrocitoma/cirurgia , Fator de Crescimento Transformador beta1/sangue , Adolescente , Adulto , Idoso , Astrocitoma/patologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Curva ROC , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
14.
Acta Neurochir (Wien) ; 154(10): 1773-9, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22772399

RESUMO

BACKGROUND: Axonal regeneration in peripheral nerves after injury is a complicated process. Numerous cytokines, growth factors, channels, kinases, and receptors are involved, and matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis subsequent to nerve injury. In this study, the effect of KMUP-1, an activator of large-conductance Ca(2+)-activated potassium channel, on functional recovery, myelinated axon growth, and immunoreactivity of MMP-9 was evaluated in rats subjected to sciatic nerve crush injury. METHOD: A total of 144 male Sprague-Dawley rats were divided into the following six groups (n = 24/group): group 1, sham-operated; group 2, sciatic nerve injury without treatment; group 3, injured and vehicle-treated; group 4, injured and treated with 1 mM KMUP-1 by topical application; group 5, injured and treated with 10 mM KMUP-1; group 6, injured and treated with 50 mM KMUP-1. Functional recovery was evaluated using walking track analysis at 1, 2, 3, and 4 weeks (n = 6/group at each time point) after injury. In addition, the number of myelinated axons and MMP-9 in the nerve was also examined. FINDINGS: Animals subjected to sciatic nerve crush injury had decreased motor function, a reduced number of myelinated axons, and increased MMP-9 in the nerve. Treatment with KMUP-1 concentration-dependently improved functional recovery, increased the number of myelinated axons, and decreased MMP-9. CONCLUSIONS: These results suggest that KMUP-1 may be a novel agent for assisting peripheral nerve recovery after injury. The beneficial effect is probably due to known ability of the compound in activating the nitric oxide/cGMP/protein kinase G pathway.


Assuntos
Axônios/efeitos dos fármacos , Regeneração Nervosa/efeitos dos fármacos , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Piperidinas/uso terapêutico , Nervo Isquiático/efeitos dos fármacos , Xantinas/uso terapêutico , Animais , Axônios/patologia , Modelos Animais de Doenças , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Compressão Nervosa/métodos , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/fisiologia , Nervo Isquiático/lesões
15.
Kaohsiung J Med Sci ; 28(6): 316-21, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22632886

RESUMO

Transforming growth factor (TGF) ß1 may be a candidate for a serologic tumor marker. In this study, the plasma levels of TGF-ß1 in patients with brain tumors were measured using enzyme-linked immunosorbent assay before and after tumor removal. Patients were divided into four groups, the control group and the benign, malignant, and metastatic brain tumor groups. All brain tumor groups showed significant increases in the levels of TGF-ß1 before tumor removal (6.36 ± 3.94, 17.0 ± 9.7, and 12.2 ± 10.3 ng/ml for the benign, malignant, and metastatic groups, respectively). When compared with the results obtained in the control group (1.12 ± 0.74 ng/ml), significant decreases in TGF-ß1 concentrations after total tumor removal were found in both the benign and malignant brain tumor groups (2.55 ± 2.00 and 8.93 ± 5.73 ng/ml, respectively; p = 0.0001 and p = 0.003, respectively). On the other hand, plasma TGF-ß1 levels in the metastatic brain tumor group showed a slight but significant increase (14.7 ± 9.3 ng/ml, p = 0.035) after tumor removal. In a case of low-grade astrocytoma, plasma levels of TGF-ß1 were found to be 3.6 and 1.1 ng/ml before and after tumor removal, respectively. However, recurrent tumor was noted in this patient 7 months later, and the levels of TGF-ß1 were 26.2 and 8.4 ng/ml before and after the second operation, respectively. The data show that plasma TGF-ß1 was elevated in the circulation of patients with brain tumors and that significant decreases in TGF-ß1 levels were observed after the removal of benign and malignant tumors. The results also suggest that TGF-ß1 may be a useful serologic marker for brain tumors.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Encefálicas/sangue , Neoplasias Encefálicas/cirurgia , Fator de Crescimento Transformador beta1/sangue , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/patologia , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
Front Pharmacol ; 2: 65, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22025914

RESUMO

Nicotinic acetylcholine receptors (nAChRs) of the cerebral cortex and cerebellum of rats were evaluated by a radioligand binding assay, employing tissue segments, or homogenates as materials. [(3)H]-epibatidine specifically bound to nAChRs in rat cortex or cerebellum, but the dissociation constants for [(3)H]-epibatidine differed between segments and homogenates (187 pM for segments and 42 pM for homogenates in the cortex and 160 pM for segments and 84 pM for homogenates in the cerebellum). The abundance of total nAChRs was approximately 310 fmol/mg protein in the segments of cortex and 170 fmol/mg protein in the segments of cerebellum, which were significantly higher than those estimated in the homogenates (115 fmol/mg protein in the homogenates of the cortex and 76 fmol/mg protein in the homogenates of the cerebellum). Most of the [(3)H]-epibatidine binding sites in the cortex segments (approximately 70% of the population) showed high affinity for nicotine (pK(i) = 7.9), dihydro-ß-erythroidine, and cytisine, but the binding sites in the cerebellum segments had slightly lower affinity for nicotine (pK(i) = 7.1). An upregulation of nAChRs by chronic administration of nicotine was observed in the cortex segments but not in the cerebellum segments with [(3)H]-epibatidine as a ligand. The upregulation in the cortex was caused by a specific increase in the high-affinity sites for nicotine (probably α4ß2). The present study shows that the native environment of nAChRs is important for a precise quantitative as well as qualitative estimation of nAChRs in rat brain.

18.
Neurosurgery ; 69(5): E1148-51, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21606882

RESUMO

BACKGROUND AND IMPORTANCE: Symptomatic lumbar disc herniation is common. Migration of a free disc fragment is usually found in rostral, caudal, or lateral directions. Posterior epidural migration is very rare. We report the first case with posterior epidural migration and sequestration into bilateral facet joints of a free disc fragment. CLINICAL PRESENTATION: A 78-year-old female presented with low back pain and right leg pain. Plain radiographs showed lumbar spondylolisthesis. Magnetic resonance imaging revealed a posterior epidural mass and intrafacet mass, which was hypointense on T1-weighted images and hyperintense on T2-weighted images. The lesion in the left L3-4 facet joint had rim enhancement, whereas the right one was not contrasted after gadolinium injection. Preoperative differential diagnosis included abscess, tumor, hematoma, or synovial cyst. An interbody cage fusion at L3-4 and L4-5 for spondylolisthesis was performed, and a hybrid technique was applied with the Dynesys flexible rod system at L3-S1 for multisegment degenerative disc disease. The lesion proved to be an epidural disc fragment with sequestration into bilateral facet joints. CONCLUSION: A free disc fragment should be considered in the differential diagnosis of posterior epidural lesions, and even in the facet joint.


Assuntos
Migração de Corpo Estranho/patologia , Deslocamento do Disco Intervertebral/patologia , Artropatias/patologia , Vértebras Lombares/patologia , Articulação Zigapofisária/patologia , Idoso , Feminino , Migração de Corpo Estranho/diagnóstico por imagem , Humanos , Deslocamento do Disco Intervertebral/complicações , Artropatias/etiologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Radiografia , Articulação Zigapofisária/cirurgia
19.
Acta Neurochir (Wien) ; 153(3): 547-55, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21161667

RESUMO

PURPOSE: Although instrumented posterior lumbar interbody fusion (PLIF) has been becoming a popular and effective method for treating degenerative lumbar scoliosis, the clinical outcome is rarely reported. We retrospectively evaluated the clinical and radiographic outcomes in patients with degenerative lumbar scoliosis after instrumented PLIF. MATERIALS AND METHODS: A total of 58 patient's clinical characteristics had been reviewed retrospectively including clinical presentations, preoperative medical comorbidities, intraoperative status, and postoperative status. Oswestry disability index (ODI), visual analog scale (VAS), and patient satisfaction were evaluated before surgery and last follow-up period. The relationship between the difference of radiographic parameter and functional outcome was evaluated. RESULTS: Functional outcomes including ODI scores and VAS were significantly improved at the last visit. The ODI was 28.1 ± 8.0 before surgery and 12.2 ± 8.8 at the last visit. VAS was 7.4 ± 2.0 before surgery and 2.4 ± 2.0 at the last visit. Patient satisfaction was 72% at the last visit. ODI was significantly related to postoperative radiographic parameters including Cobb's angle (p < 0.001), L4 inclination (p = 0.011), coronal balance (p = 0.007), lateral vertebral translation (p < 0.001), Nash-Moe grade (p = 0.033), Nash-Moe degree (p = 0.025), and sagittal balance (p = 0.041) Using multiple regression analysis, ODI was significantly related to female gender, number of levels fixed, coronal balance, lateral vertebral translation, and Nash-Moe degree. The was no significant correlation between postoperative radiographic parameters and pain (VAS). Only lateral vertebral translation demonstrated a significant correlation in multiple regression analysis. CONCLUSIONS: Based on the VAS and ODI instrument, our studies demonstrated that instrumented PLIF for adult degenerative lumbar scoliosis can achieve a high rate of patient satisfaction and improvement in radiographic and clinical outcomes at a minimum of 2 years of follow-up.


Assuntos
Vértebras Lombares/cirurgia , Complicações Pós-Operatórias/etiologia , Escoliose/cirurgia , Fusão Vertebral/métodos , Espondilose/cirurgia , Idoso , Idoso de 80 Anos ou mais , Avaliação da Deficiência , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade
20.
Neurosci Lett ; 479(1): 6-9, 2010 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-20471451

RESUMO

It has been established that insulin secretion is regulated by autonomic nervous homeostasis. In the screen of plasma glucose level, anesthetized animals were widely used. However, effects of anesthetics on blood glucose remain unclear. In the present study, we compared the hypoglycemic action of ginseng that was induced by insulin secretion in mice between conscious and under anesthesia with pentobarbital. The hypoglycemic effect of ginseng was only produced in anesthetized BALB/c mice but not in the conscious mice. Similar results were also observed in C57BL/6 mice. However, the hypoglycemic action of ginseng failed to produce in anesthetized BALB/c mice received streptozotocin to induce type-1 like diabetes showing an insulin-dependent manner. The plasma insulin level in anesthetized BALB/c mice was markedly raised by ginseng but this effect was not observed in conscious mice. Blockade of muscarinic receptors by atropine inhibited ginseng-induced insulin secretion in anesthetized mice. Otherwise, the hypoglycemic action of ginseng was restored in conscious mice treated guanethidine at a sufficient dose to block sympathetic tone. In conclusion, the obtained results suggest that insulin secretion regulated by autonomic nervous homeostasis can be changed by pentobarbital through decrement in sympathetic tone to increase the insulin secretion induced by agent(s) via higher of parasympathetic tone. This finding is suitable to explain the critical hypoglycemia was not observed in subjects received ginseng.


Assuntos
Adjuvantes Anestésicos/farmacologia , Sistema Nervoso Autônomo/efeitos dos fármacos , Sistema Nervoso Autônomo/fisiologia , Glicemia/análise , Insulina/metabolismo , Pentobarbital/farmacologia , Anestesia , Animais , Sistema Nervoso Autônomo/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Homeostase , Hipoglicemiantes/farmacologia , Secreção de Insulina , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Panax , Preparações de Plantas/farmacologia , Especificidade da Espécie
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