RESUMO
BACKGROUND: Oxidative stress is an imbalance between the levels of reactive oxygen species (ROS), reactive nitrogen species (RNS) and endogenous antioxidants. The aetiology and pathogenesis of several oral diseases are attributed to this process. The antioxidant enzymes secreted in the saliva by submandibular glands maintain oral health through the scavenging of ROS. The objective of this work was to study the capacity of an aqueous extract of L. divaricata (AE), and its majority compound, nordihydroguariaretic acid (NDGA), to modulate the pro-oxidant/antioxidant status in submandibular glands in a model of oxidative stress induced by streptozotocin (STZ) in rats. METHODS: To induce oxidative stress with STZ, a group of animals was treated i.p. with 1 X PBS (control group) and other group was injected i.p. once with STZ (60 mg/kg). Ten days after the treatment, blood samples were taken from the tail vain to determine the glucose levels. Animals with glucose values ≥300 mg/ml were selected. The submandibular glands of control and STZ treated animals were incubated with either the AE (500 µg/ml) or with NDGA (1.5 µg/ml), and the content of malondialdehyde (MDA), protein carbonyl groups, ROS and RNS, and the activity and expression of peroxidase (Px), superoxide dismutase (SOD) and inducible nitric oxide synthase (iNOS) were assayed. RESULTS: AE decreased the levels of MDA (##P < 0.01) and protein carbonyl groups (#P < 0.05), and modulated the levels of ROS such as hydrogen peroxide (H2O2)(##P < 0.01), superoxide anion (O2.-) (#P < 0.05) and nitric oxide (NO) (#P < 0.05) in relation to the modulation of Px and iNOS expression. NDGA was found to be involved in these effects. CONCLUSIONS: The antioxidant activity of the AE in the submandibular glands would allow the maintenance of the antioxidant pool to prevent oral oxidative diseases.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Larrea/química , Masoprocol/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Glândula Submandibular/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Feminino , Malondialdeído/análise , Oxirredutases/análise , Ratos , Ratos Wistar , Glândula Submandibular/química , Glândula Submandibular/enzimologiaRESUMO
Glutamate decarboxylase or glutamic acid decarboxylase (GAD) is a protein associated with autoimmune diseases, including type-1 diabetes. This disease is primarily associated with the occurrence of a specific isoform: GAD65. Conversely, some specific peptides of this protein may block autoimmunity in diabetes. In this respect, understanding the relationship between GAD and the development of diabetes is important, and it is necessary to understand the role of each GAD peptide to design effective autoimmune diabetes treatments. The purpose of the present study was to analyze the effects of treatment with GAD-derived peptides p217 and p290 on INS receptors in the salivary epithelium of nonobese diabetic (NOD) animals. Three groups of 7 mice each were studied: I, BALB/c mice (control); II, NOD mice; and III, NOD mice treated with peptides p290 and p217. Groups I and II only received buffered saline solution. Glucose levels were measured daily during the 21 days of the experiment. After the study, the animals were euthanized and the parotid and submandibular glands were removed for the analysis of INS-R by fluorescence microscopy. Therapy with two peptides together was associated with reduced glucose levels in NOD mice and intense INS-R expression in both salivary organs. Our approach of combining GAD p217 and p290 peptides contributed to hormonal balance and promoted the repair of INS-R.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Células Epiteliais/efeitos dos fármacos , Glutamato Descarboxilase/metabolismo , Hipoglicemiantes/farmacologia , Glândula Parótida/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Receptor de Insulina/metabolismo , Glândula Submandibular/efeitos dos fármacos , Animais , Biomarcadores/sangue , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/enzimologia , Diabetes Mellitus Tipo 1/patologia , Modelos Animais de Doenças , Células Epiteliais/enzimologia , Células Epiteliais/patologia , Feminino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Glândula Parótida/enzimologia , Glândula Parótida/patologia , Glândula Submandibular/enzimologia , Glândula Submandibular/patologiaRESUMO
BACKGROUND: We demonstrate that serum immunoglobulin G (IgG) directed against glandular M3 muscarinic acetylcholine receptors (M3mAChR) and pilocarpine triggers the increment of superoxide dismutase (SOD) and catalase (CAT) and the production of nitric oxide (NO) and prostaglandin E2(PGE2). METHODS: Enzyme-linked immunosorbent assay (ELISA) was performed in the presence of the human M2mAChR synthetic peptide as antigen to detect in serum of pSS patients the autoantibodies. Further, SOD and CAT specific activity and NO were determined chemically in the presence of anti-M3mAChR IgG and pilocarpine. The level of PGE2generation in the presence of autoantibody and pilocarpine was determined by ELISA. RESULTS: An association between anti-M2mAChR autoantibodies and pilocarpine given the increment of the specific activity of SOD and CAT in the serum of pSS patients and in the rat submandibular gland was observed. As a result of this action, M3synthetic peptide and atropine abrogated the stimulatory action. The L-type calcium channel, calcium/calmodulin complex and COX-2 inhibitors selectively blocked the increment of the specific activity of SOD and CAT in the rat submandibular gland. An increased production of NO and PGE2by the cholinergic autoantibody and pilocarpine was also detected. CONCLUSION: On the basis of these results, the increment of the specific activity of SOD and CAT in pSS patients as compared to control healthy individuals may be seen as a defensive reaction to the increment of the amount of ROS, which becoming uncontrollable, leads to irreversible cellular and tissue damage.
Assuntos
Antioxidantes/metabolismo , Imunoglobulina G/farmacologia , Receptor Muscarínico M3/imunologia , Síndrome de Sjogren/enzimologia , Síndrome de Sjogren/imunologia , Glândula Submandibular/enzimologia , Acetilcolina , Adulto , Sequência de Aminoácidos , Animais , Autoanticorpos/sangue , Autoanticorpos/farmacologia , Catalase/sangue , Inibidores de Ciclo-Oxigenase 2/farmacologia , Dinoprostona/biossíntese , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Óxido Nítrico/metabolismo , Pilocarpina/farmacologia , Ratos , Ratos Wistar , Receptores de IgG/metabolismo , Síndrome de Sjogren/terapia , Glândula Submandibular/efeitos dos fármacos , Superóxido Dismutase/sangueRESUMO
Many studies suggest that fluoride exposure can inhibit the activity of various enzymes and can generate free radicals, which interfere with antioxidant defence mechanisms in living systems. To further the understanding of this issue, this present study examined the effects of low-dose fluoride treatment on the activity of enzymatic antioxidant superoxide dismutase (SOD) and catalase (CAT), as well as the levels of lipid peroxidation (LPO) in the parotid (PA) and submandibular (SM) salivary glands of rats. Rats were injected with a single dose of sodium fluoride (NaF) (15 mg F(-)/kg b.w.) then euthanized at various time intervals up to 24 hours (h) following exposure. NaF exposure did not cause significant differences in SOD or CAT activity or LPO levels in PA glands compared to control. Conversely, SM glands presented increased SOD activity after 3 h and decreased SOD activity after 1, 12, and 24 h, while LPO was increased after 6, 12, and 24 h of the NaF injection. There were no significant differences in the CAT activity in the groups studied. Our results demonstrated that NaF intoxication caused oxidative stress in salivary glands few hours after administration. These changes were more pronounced in SM than in PA gland.
Assuntos
Antioxidantes/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Glândulas Salivares/enzimologia , Fluoreto de Sódio/farmacologia , Animais , Catalase/metabolismo , Masculino , Malondialdeído/metabolismo , Glândula Parótida/efeitos dos fármacos , Glândula Parótida/enzimologia , Ratos , Ratos Wistar , Glândulas Salivares/efeitos dos fármacos , Glândula Submandibular/efeitos dos fármacos , Glândula Submandibular/enzimologia , Superóxido Dismutase/metabolismoRESUMO
BACKGROUND: Amylase is synthesized in submandibular glands (SMG) and released into the oral cavity to degrade carbohydrates in the mouth. Bitter taste receptors (T2R) belong to the G-protein coupled receptor (GPCR) family and are expressed in the taste cells and also in the digestive tract. METHODS: The activity of amylase secreted by murine SMG was measured, detecting maltose by Bernfeld's method. Amylase and T2R6 were detected by imunohistochemistry and Western blot. The expression of Ggustducin, Gi, and phospholipase Cß2 was also studied by Western blot. cAMP levels were measured by radioimmunoassay and inositol monophosphate production was quantified by ELISA. RESULTS: Theophylline, denatonium and cycloheximide exerted a dose-dependent inhibition on amylase secretion. This effect was reverted by preincubating SMG with an anti-Gαi antibody. cAMP production was increased by the same compounds, an effect that was also abrogated by an anti-Gαi antibody. Bitter compounds reduced inositol monophosphate formation in SMG and H-89, a protein kinase A inhibitor, reverted this action, revealing that this protein kinase down regulates phospholipase C activity. GENERAL SIGNIFICANCE: We demonstrated that theophylline, denatonium and cycloheximide inhibit salivary amylase secretion, activating an intracellular signaling pathway that involves cAMP and phospholipase C, that cross talks via protein kinase A.
Assuntos
Amilases/metabolismo , Transdução de Sinais , Glândula Submandibular/enzimologia , Animais , Western Blotting , AMP Cíclico/metabolismo , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Glândula Submandibular/metabolismoRESUMO
The salivary glands are important exocrine and endocrine organs, whose role in oral health is well recognized. Also these glands contribute to the maintenance of systemic health. During diabetes an impairment of salivary glands is reported. In this work the oxidative stress produced after 10days of a single dose of streptozotocin administration in rats was observed in submandibulary glands. Under this condition a misbalance of the enzymes with antioxidant activity was observed in glands and in incubation medium, as well as in reactive oxygen species such as hydrogen peroxide (H(2)O(2)), superoxide anion (O(2)(-)) and nitric oxide (NO). An increase of NO and H(2)O(2) and a decrease of O(2)(-) were found. A direct relationship between peroxidase and nitric oxide synthase (iNOS) activities with enzyme expression was recorded, in contrast an inverse relationship between superoxide dismutase activity and expression was observed. If the high level of H(2)O(2) persists in time as well as a low level of peroxidase, oral pathologies are expected to occur. So, under this situation to study the modulation of enzymes involved in reactive oxygen species metabolism during oxidative stress in oral tissues could be very important in the managing of oral pathologies.
Assuntos
Antioxidantes/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Estreptozocina/farmacologia , Glândula Submandibular/efeitos dos fármacos , Glândula Submandibular/metabolismo , Animais , Ativação Enzimática/efeitos dos fármacos , Feminino , Oxirredução/efeitos dos fármacos , Oxirredutases/metabolismo , Ratos , Ratos Wistar , Glândula Submandibular/enzimologiaRESUMO
We demonstrate that patients with primary Sjögren's syndrome (pSS) produce functional IgG autoantibodies that interact with the glandular M(3) muscarinic acetylcholine receptors (mAChRs). These autoantibodies act as a partial muscarinic agonist, increasing prostaglandin E(2) (PGE(2)) and cyclic AMP production through modifying Na(+)/K(+)-ATPase activity, but also interfere with the secretory effect of the parasympathetic neurotransmitter. The IgG from patients with pSS has two effects on the submandibular gland. On the one hand, it may act as an inducer of the proinflammatory molecule (PGE(2)) that, in turn, inhibits Na(+)/K(+)-ATPase activity. On the other hand, it plays a role in the pathogenesis of dry mouth, abolishing the Na(+)/K(+)-ATPase inhibition and the net K(+) efflux stimulation of the salivary gland in response to the authentic agonist pilocarpine, decreasing salivary fluid production.
Assuntos
Autoanticorpos/imunologia , AMP Cíclico/metabolismo , Dinoprostona/metabolismo , Imunoglobulina G/imunologia , Agonistas Muscarínicos/imunologia , Receptor Muscarínico M3/imunologia , Síndrome de Sjogren/imunologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Glândula Submandibular/enzimologia , Adulto , Animais , Células Cultivadas , Feminino , Humanos , Fatores Imunológicos/imunologia , Mediadores da Inflamação/imunologia , Ceratoconjuntivite Seca/imunologia , Masculino , Pessoa de Meia-Idade , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Pilocarpina/farmacologia , Piperidinas/farmacologia , Pirenzepina/farmacologia , Potássio/metabolismo , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Glândula Submandibular/efeitos dos fármacos , Glândula Submandibular/metabolismo , Tropicamida/farmacologia , Xerostomia/imunologiaRESUMO
OBJECTIVE: The aim of this study was to evaluate the effect of laser irradiation on the amylase and the antioxidant enzyme activities, as well as on the total protein concentration of submandibular glands (SMG) of diabetic and non-diabetic rats. BACKGROUND: Laser has been used aiming to improve some biochemical alterations observed in salivary glands of streptozotocin-induced diabetic rats. MATERIALS AND METHODS: Ninety-six female rats were divided into eight groups: D0, D5, D10, and D20 (diabetic animals), and C0, C5, C10, and C20 (non-diabetic animals), respectively. Diabetes was induced by administering streptozotocin and confirmed later by the glycemia results. Twenty-nine days after diabetes induction, the SMG of groups D5 and C5, D10 and C10, and D20 and C20 were irradiated with 5, 10, and 20 J/cm(2), respectively. A diode laser (660 nm/100 mW) was used. On the day after irradiation, the rats were euthanized and the SMG were removed. Catalase, peroxidase, and amylase activities, as well as protein concentration, were assayed. RESULTS: Diabetic rats without irradiation (D0) showed higher catalase activity (p < 0.05) when compared to C0 (0.16 +/- 0.05 and 0.07 +/- 0.01 U/mg protein, respectively). However, laser irradiation of 5, 10, and 20 J/cm(2) reduced the catalase activity of diabetic groups (D5 and D20) to non-diabetic values (p > 0.05). CONCLUSION: Based on the results of this study, laser irradiation decreased catalase activity in diabetic rats' SMG.
Assuntos
Catalase/metabolismo , Diabetes Mellitus Experimental/enzimologia , Lasers Semicondutores , Glândula Submandibular/enzimologia , Glândula Submandibular/efeitos da radiação , Amilases/metabolismo , Análise de Variância , Animais , Feminino , Peroxidase/metabolismo , Proteínas/metabolismo , RatosRESUMO
Xerostomia is commonly caused by antidepressant drugs and ATP can influence the saliva production. Adenosine is the product of extracellular hydrolysis of adenine nucleotides in submandibular gland cells, which occurs by the action of ectonucleotidases. In this study, we have evaluated the effect of three different antidepressants in ecto-nucleotide pyrophosphatase/phosphodiesterase (E-NPP1-3) activities in cultured cells from salivary glands. Rats received imipramine (10mg/ml), fluoxetine (20mg/ml) or moclobemide (30mg/ml) by oral gavage. The drugs were administered once a day for 14 days. Our results have shown that the hydrolysis of p-nitrophenyl-5'-thymidine monophosphate increased in all treatments. These effects were not consequence of transcriptional control of E-NPP1-3 genes. The results reported here can highlight the importance of ectonucleotidases in the most common side effect caused by antidepressant therapy.
Assuntos
Antidepressivos/farmacologia , Diester Fosfórico Hidrolases/efeitos dos fármacos , Pirofosfatases/efeitos dos fármacos , Glândula Submandibular/enzimologia , Animais , Antidepressivos de Segunda Geração/farmacologia , Antidepressivos Tricíclicos/farmacologia , Células Cultivadas , Fluoxetina/farmacologia , Hidrólise , Imipramina/farmacologia , Masculino , Moclobemida/farmacologia , Diester Fosfórico Hidrolases/análise , Fosforilação , Pirofosfatases/análise , Ratos , Ratos Wistar , Proteínas e Peptídeos Salivares/análise , Proteínas e Peptídeos Salivares/efeitos dos fármacos , Glândula Submandibular/citologia , Glândula Submandibular/efeitos dos fármacos , Timidina Monofosfato/análogos & derivados , Timidina Monofosfato/análise , Fatores de TempoRESUMO
Diabetes has been implicated in the dryness of the mouth, loss of taste sensation, sialosis, and other disorders of the oral cavity, by impairment of the salivary glands. The aim of the present study was to examine the plasma membrane, microsomal, and homogenate Ca(2+)-ATPase activity in the rat submandibular and parotid salivary glands of streptozotocin-induced diabetes. We have also examined the influence of the acidosis state on this parameter. Diabetes was induced by an intraperitoneal injection of streptozotocin and acidosis was induced by daily injection of NH(4)Cl. At 15 and 30 days after diabetes induction, the animals were euthanized and the submandibular and parotid salivary glands were removed and analyzed. Ca(2+)-ATPase (total, independent, and dependent) was determined in the homogenate, microsomal, and plasma membranes of the salivary glands of diabetic and control rats. Calcium concentration was also determined in the glands and showed to be higher in the diabetic animals. Ca(2+)-ATPase activity was found to be reduced in all cell fractions studied in the diabetic animals compared with control. Similar results were obtained for the submandibular salivary glands of acidotic animals; however in the parotid salivary glands it was found an increase in the enzyme activity.