Exposure to lipopolysaccharide and calcium silicate-based materials affects the behavior of dental pulp cells

Abstract This study assessed the cell viability, cytokine production, and mineralization potential of human dental pulp cells (hDPCs) after exposure to lipopolysaccharide (LPS) and application of calcium silicate-based materials (CSBM). Characterization of the CSBM was performed by infrared spectroscopy (n = 3). Extracts of Bio-C Repair, Biodentine, Cimmo HD, and MTA Repair HP were prepared and diluted (1:1, 1:4, and 1:16). Culture of hDPCs was established and treated or not with 1 µg/mL of LPS from Escherichia coli for 7 days. MTT assay was used to assess cell viability at 24, 48, and 72 h (n = 6). Alkaline phosphatase (ALP) activity was assayed on day 7 (n = 4). Il-10 and TNF-α were quantified by ELISA at 24 h (n = 6). Data were analyzed by ANOVA and Tukey's test (α = 0.05). Cell viability of LPS-activated hPDCs was higher than untreated control in 48 and 72 h (p < 0.05). Differences between non-treated and LPS-activated hPDCs were observed for Biodentine and Cimmo HP (p < 0.05). The CSBM influenced the cell viability (p < 0.05). ALP activity was higher in LPS-activated hDPCs (p < 0.05). No changes in the concentration of TNF-α were observed between groups (p > 0.05). The CSBM increased the Il-10 production (p < 0.05). LPS-activated hDPCs presented increased cell viability and ALP activity. The CSBM showed mild toxicity and was able to enhance the cell viability and mineralization potential of untreated and LPS-activated hDPCs. The CSBM also induced anti-inflammatory mechanisms without compromising pro-inflammatory ones.

Resumo Este estudo avaliou a viabilidade celular, produção de citocinas e potencial de mineralização de células da polpa dentária humana (hDPCs) após exposição a lipopolissacarídeo (LPS) e aplicação de materiais à base de silicato de cálcio (CSBM). A caracterização do CSBM foi realizada por espectroscopia (n = 3). Extratos de Bio-C Repair, Biodentine, Cimmo HD e MTA Repair HP foram preparados e diluídos (1: 1, 1: 4 e 1:16). A cultura de hDPCs foi estabelecida e tratada ou não com 1 µg / mL de LPS de Escherichia coli por 7 dias. O ensaio de MTT foi usado para avaliar a viabilidade celular em 24, 48 e 72 h (n = 6). A atividade da fosfatase alcalina (ALP) foi avaliada no dia 7 (n = 4). Il-10 e TNF-α foram quantificados por ELISA em 24 h (n = 6). Os dados foram analisados ​​por ANOVA e teste de Tukey (α = 0,05). A viabilidade celular das hPDCs ativados por LPS foi maior do que o controle não tratado em 48 e 72 h (p <0,05). Diferenças entre hPDCs não tratados e ativados por LPS foram observados para Biodentine e Cimmo HP (p < 0,05). Os CSBM influenciaram na viabilidade celular (p <0,05). A atividade de ALP foi maior em hDPCs ativadas por LPS (p <0,05). Não foram observadas alterações na concentração de TNF-α entre os grupos (p> 0,05). Os CSBM aumentaram a produção de Il-10 (p < 0,05). Os hDPCs ativados por LPS apresentaram um aumento na viabilidade celular e atividade ALP. Os CSBM apresentaram toxicidade moderada e foram capazes de aumentar a viabilidade celular e o potencial de mineralização de hDPCs não tratados e ativados por LPS. Os CSBM também induziram mecanismos anti-inflamatórios sem comprometer os pró-inflamatórios.

Response of periodontal ligament stem cells to lipopolysaccharide and calcium silicate-based materials

Abstract This study was conducted to assess the in vitro response of human periodontal ligament stem cells (hPDLSCs) to bacterial lipopolysaccharide (LPS) activation and application of three calcium silicate-based materials (CSBM): Bio-C Sealer, MTA Fillapex and Cimmo HP. Characterization of the CSBM was performed by FTIR (n = 3). Extracts of Bio-C Sealer, MTA Fillapex and Cimmo HP were prepared and diluted (1:1, 1:4 and 1:16). Culture of hPDLSCs was established and treated or not with LPS from Escherichia coli (1 µg/mL) for 7 days. MTT assay was used to assess cell viability at 24, 48 and 72 h (n = 9). Alkaline phosphatase (ALP) activity was indirectly assayed at day 7 (n = 5). TNF-α and Il -1 0 cytokines were quantified by ELISA at 24h-cell supernatants (n = 6). Data were analyzed by ANOVA and Tukey's test (α = 0.05). The cell viability of the LPS-activated hPDLSCs were higher than untreated control (p < 0.05). The application of CSBM affected the cell viability of untreated and LPS-activated cells (p < 0.05). ALP activity was higher for Bio-C Sealer and Cimmo HP in untreated and LPS-activated cells, respectively (p < 0.05). Application of CSBM normalized the TNF-α secretion in the LPS-activated cells (p < 0.05). Only MTA Fillapex in untreated hPDLSCs presented higher values of Il -1 0 (p < 0.05). Taken collectively, the results suggests that the simulation of the inflammatory process by LPS affect the in vitro response the hPDLSCs to the application of the CSBM.

Resumo Este estudo objetivou avaliar a resposta in vitro de células-tronco do ligamento periodontal humano (hPDLSCs) à ativação por lipopolissacarídeo bacteriano (LPS) e aplicação de três materiais à base de silicato de cálcio (CSBM): Bio-C Sealer, MTA Fillapex e Cimmo HP. A caracterização dos CSBM foi realizada por FTIR (n = 3). Extratos de Bio-C Sealer, MTA Fillapex e Cimmo HP foram preparados e diluídos (1:1, 1: 4 e 1:16). A cultura de hPDLSCs foi estabelecida e tratada ou não com 1 µg / mL de LPS de Escherichia coli por 7 dias. O ensaio de MTT foi usado para avaliar a viabilidade celular em 24, 48 e 72 h (n = 9). A atividade de ALP foi avaliada indiretamente no dia 7 (n = 5). As citocinas TNF-α e Il-10 foram quantificadas por ELISA em sobrenadantes de células em 24h (n = 6). Os dados foram analisados por ANOVA e teste de Tukey (α = 0,05). A viabilidade celular das hPDLSCs ativados por LPS foi maior do que o controle (p <0,05). A aplicação dos CSBM afetou a viabilidade celular de células ativadas ou não por LPS (p <0,05). A atividade de ALP foi maior para Bio-C Sealer e Cimmo HP em células não ativadas e ativadas por LPS, respectivamente (p <0,05). A aplicação dos CSBM normalizou a secreção de TNF-α nas células ativadas por LPS (p <0,05). Apenas o MTA Fillapex em hPDLSCs não ativadas apresentou valores mais elevados de Il-10 (p <0,05). Em conclusão, os resultados sugerem que a simulação do processo inflamatório por LPS afetou a resposta in vitro de células-tronco do ligamento periodontal e de materiais à base de silicato de cálcio.

Antioxidant effect of chamomile tea on the salivary glands of streptozotocin-induced diabetic rats

Abstract: This study aimed to analyze oxidative stress and the activity of antioxidant enzymes in the salivary glands of streptozotocin (STZ)-induced diabetic rats with ad libitum consumption of chamomile tea in substitution of water for 21 days. Rats were divided in two control groups (untreated control and treated control) and two diabetic groups (untreated diabetic and treated diabetic). Superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) activities, total antioxidant status (TAS), and malondialdehyde (MDA) concentrations were determined. The chemical composition of the chamomile essential oil revealed 39 compounds, accounting for 93.5% of the total oils. The polyphenolic profile of the tea showed the presence of apigenin, luteolin, umbelliferone, and esculetin. SOD, GPx, CAT, and TAS levels were lower in the parotid (PA) diabetic glands, but treatment increased their concentration in both the submandibular (SM) and PA diabetic salivary glands. Increased MDA levels were observed in the PA diabetic glands, which were decreased by the consumption of chamomile tea with a reduction in hyperglycemia compared to that in untreated diabetic rats. However, the SM diabetic glands showed no difference in the MDA content. The consumption of chamomile tea prevented oxidative stress in the PA glands of diabetic rats, exhibiting hypoglycemic and antioxidant effects. Thus, chamomile tea could be a potential candidate for preventing oral complications in diabetes mellitus.

Cytotoxicity of Reparative Endodontic Cements on Human Periodontal Ligament Stem Cells

ABSTRACT Objective To compare the cytotoxicity of commercial reparative endodontic cements on human periodontal ligament stem cells (hPDLSCs). Material and Methods The culture of hPDLSCs was established. Cell density was set at 2 × 104 cells/well in 96-well plates. Extracts of Biodentine, Bio-C Repair, Cimmo HD, MTA Repair HP and White MTA were prepared. Then, the extracts were diluted (pure, 1:4 and 1:16) and inserted into cell-seeded wells for 24, 48, and 72 h to assess cell viability through MTT assay. hPDLSCs incubated with culture medium alone served as a negative control group. Data were analyzed by Two-Way ANOVA and Tukey's test (α=0.05). Results At 24 h, pure extract of MTA Repair HP and Biodentine 1:16 presented higher cell viability compared to control. Lower cell viability was found for pure extract of Cimmo HD, MTA Repair HP 1:4 and 1:16, and White MTA 1:16. At 48 h, pure extract of Bio-C Repair and MTA Repair HP presented higher cell viability compared to control. At 72 h, only the pure extract of MTA Repair HP led to higher cell proliferation compared to control. Conclusion Biodentine, Bio-C Repair and MTA Repair HP were able to induce hPDLSCs proliferation. Cimmo HD and White MTA were found to be mostly cytotoxic in hPDLSCs.

Calcium silicate-based cements affect the cell viability and the release of TGF-β1 from apical papilla cells

Abstract This study investigated the cytotoxicity and release of Transforming Growth Factor Beta 1 (TGF-β1) from cultured human apical papilla cells (APCs) after application of four bioactive materials. Culture of APCs was established and used for cytotoxic and quantitative assays. Extracts of Biodentine, Bio-C Repair, MTA Repair and White MTA were prepared and diluted (1, 1:4 and 1:16) and used for MTT assays up to 72 h. Total TGF-β1 was quantified by ELISA. Data were analyzed by ANOVA and Tukey's test (α = 0.05). For Biodentine, at 24 h and 48 h, cell viability was lower than control (p < 0.05). At 72 h, only undiluted extract of Biodentine were cytotoxic (p < 0.05). At 24 h, a cytotoxic effect was found for undiluted and 1:4 dilution of Bio-C Repair (p < 0.05). At 48 h, however, Bio-C Repair at 1:4 and 1:8 dilution showed higher cell viability (p < 0.05). At 24 and 48 h, the cell viability for undiluted MTA Repair were higher than control (p < 0.05). For White MTA, at 24 and 48 h, all dilutions were cytotoxic (p < 0.05). All cements led to reduced release of total TGF-β1 from the APCs (p < 0.05). In conclusion, cell viability varied depending on the material and dilution. Only Bio-C repair and MTA repair led to higher cell viability of APCs. All materials induced a decrease in the release of total TGF-β1 from the APCs.

Resumo Este estudo investigou a citotoxicidade e liberação do Fator de Crescimento Transformador Beta 1 (TGF-β1) em células da papila apical humana (APCs) cultivadas após a aplicação de quatro materiais bioativos. A cultura de APCs foi estabelecida e usada para ensaios citotóxicos e quantitativos. Extratos de Biodentine, Bio-C Repair, MTA Repair e White MTA foram preparados e diluídos (1, 1: 4 e 1:16) e usados para ensaios de MTT por até 72 h. O TGF-β1 total foi quantificado por ELISA. Os dados foram analisados por ANOVA e teste de Tukey (α = 0,05). Para o Biodentine, em 24 h e 48 h, efeito citotóxico foi observado (p <0,05). Em 72 h, apenas o extrato não diluído de Biodentine teve efeito citotóxico (p <0,05). Em 24 h, valores mais baixos de viabilidade celular foram encontrados para o extrato não diluído e diluidi 1:4 de Bio-C Repair (p <0,05). Em 48 h, no entanto, Bio-C Repair na diluição 1:4 e 1:8 mostrou maior viabilidade celular (p <0,05). A viabilidade celular para MTA Repair não diluído em 24 e 48 h foi maior que o controle (p <0,05). Para White MTA, às 24 e 48 h, a viabilidade celular em todas as diluições foram citotóxicas (p <0,05). Todos os cimentos levaram à redução da liberação de TGF-β1 total das APCs (p <0,05). Em conclusão, a viabilidade celular variou dependendo do material e da diluição. Biodentine, Bio-C Repair e MTA Repair levaram a uma maior viabilidade celular de APCs. Todos os materiais induziram uma diminuição na liberação de TGF-β1 total das APCs.

Cytotoxicity and cytokine production by calcium silicate-based materials on periodontal ligament stem cells

Abstract This study investigated the effect of three commercial calcium silicate-based materials (CSBM) on cytotoxicity and pro-and anti-inflammatory cytokines production in cultured human periodontal ligament stem cells (hPDLSCs). Culture of hPDLSCs was established and characterized. Extracts of Bio-C Sealer (Angelus, Londrina, PR, Brazil), MTA Fillapex (Angelus, Londrina, PR, Brazil) and PBS Cimmo HP (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brazil) were prepared by placing cement specimens (5 x 3 mm) in culture medium. Then, the extracts were serially two-fold diluted (1, 1:2, 1:4, 1:8, 1:16) and inserted into the cell-seeded wells for 24, 48 and 72 h for MTT assays. TNF-α and IL-10 cytokines were quantified by ELISA at 24h-cell supernatants. Data were analyzed by ANOVA and Tukey's test (α = 0.05). All CSBM exhibited some cytotoxicity that varied according to extract concentration and time of evaluation. MTA Fillapex presented the highest cytotoxic effects with significant reduction of metabolic activity/cell viability when compared to Bio-C Sealer and Cimmo HP®. TNF-α was significantly upregulated by the three tested cements (p < 0.05) while only MTA Fillapex significantly upregulated IL-10 in comparison to control. Taken collectively, the results showed that PBS Cimmo HP®, Bio-C Sealer and MTA Fillapex present mild and transient cytotoxicity and slightly induced TNF-α production. MTA Fillapex upregulated IL-10 release by hPDLSCs.

Resumo Este estudo investigou o efeito de três materiais comerciais à base de silicato de cálcio (CSBM) na citotoxicidade e na produção de citocinas pró e antiinflamatórias em células-tronco do ligamento periodontal humano (hPDLSCs). Cultura de hPDLSCs foi estabelecida e caracterizada. Extratos de Bio-C Sealer (Angelus, Londrina, PR, Brasil), MTA Fillapex (Angelus, Londrina, PR, Brasil) e PBS Cimmo HP® (Cimmo Soluções em Saúde, Pouso Alegre, MG, Brasil) foram preparados com a colocação de espécimes dos cimentos (5 x 3 mm) em meio de cultura. Em seguida, os extratos foram diluídos (1, 1: 2, 1: 4, 1: 8, 1:16) e inseridos nos poços semeados de células para ensaio de citotoxicidade por meio de MTT por 24, 48 e 72 h. As citocinas TNF-α e IL-10 foram quantificadas por ELISA em sobrenadantes de células de 24 h. Os dados foram analisados por ANOVA e teste de Tukey (α = 0,05). Todos os CSBM exibiram alguma citotoxicidade que variou de acordo com a concentração do extrato e o tempo de avaliação. O MTA Fillapex apresentou os maiores efeitos citotóxicos com redução significativa da atividade metabólica / viabilidade celular quando comparado ao Bio-C Sealer e Cimmo HP®. O TNF-α foi regulado positivamente pelos três cimentos testados (p <0,05), enquanto apenas o MTA Fillapex regulou positivamente a liberação de IL-10 em comparação com o controle. Tomados em conjunto, os resultados mostraram que PBS Cimmo HP®, Bio-C Sealer e MTA Fillapex apresentam citotoxicidade leve e transitória e induziram a produção de TNF-α. O MTA Fillapex regulou positivamente a liberação de IL-10 por hPDLSCs.

Salivary Glands, Saliva and Oral Findings in COVID-19 Infection

Abstract The world is under the threat of the novel coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite several efforts to contain the disease spread, it still constitutes a public health emergency of international concern. Several published reports in the scientific literature called attention of the oral cavity as the potential route of infection, the implications for dental practice and the use of saliva in the diagnose of the COVID-19. The aim of this article is to provide an overview of the literature on the salivary glands and saliva in the context of SARS-CoV-2 infection. A brief discussion of taste disturbances and oral findings in COVID-19 patients is also presented. The literature shows that SARS-CoV-2 could infect the salivary glands. It is not possible, however, to make speculations regarding them as reservoirs for the SARS-CoV-2. In addition, patients with COVID-19 presented several oral repercussions, including hyposalivation and taste disturbances. A few reports showed oral ulcers and blisters associated with SARS-CoV-2 infection. However, it remains not fully understood and might lead to erroneous assumptions. Overall, further studies are necessary to understand the real role of salivary glands and saliva in the context of SARS-CoV-2 infection.

Assessment of oxidative stress in saliva of children with dental erosion / Avaliação do estresse oxidativo da saliva de crianças com erosão dentária

ABSTRACT Objective To evaluate oxidative stress in saliva of children with dental erosion as compared to children with no erosion. Methods One single examiner, trained and prepared to make diagnosis of dental erosion according to the Basic Erosive Wear Examination index, selected 40 children aged 4 to 6 years, who attended a pediatric dentistry prevention clinic. Two groups were formed - one comprising children with dental erosion (n=22), and another with no dental erosion (n=18). The quantity of dental biofilm was verified using the Simplified Index of Oral Hygiene, and unstimulated saliva was collected for biochemical analyses. The following were assessed in saliva: flow rate, buffering capacity, pH, and total protein concentration. Malondialdehyde levels were also verified to determine oxidative stress and total antioxidant status. Results The quantity of biofilm was smaller in children with mean dental erosion±standard deviation (0.76±0.25), as compared to those with no dental erosion (1.18±0.28). There was no statistical difference in saliva parameters of oxidative stress in children with dental erosion. Conclusion The activity of oxidative stress in saliva did not influence dental erosion process when in its early stages.

RESUMO Objetivo Avaliar o estresse oxidativo da saliva de crianças que possuíam erosão dentária, comparadas àquelas que não apresentavam esta situação. Métodos Um único examinador, treinado e calibrado para o diagnóstico de erosão dentária, segundo o índice de Basic Erosive Wear Examination, selecionou 40 crianças de 4 a 6 anos de idade que frequentavam uma clínica de prevenção de odontopediatria. Dois grupos foram formados - um com aquelas que apresentavam erosão (n=22) e outro sem erosão (n=18). A quantidade do biofilme dental foi obtida utilizando o Índice de Higiene Oral Simplificado, tendo sido feita a coleta de saliva não estimulada para as análises bioquímicas. O fluxo salivar, a capacidade tampão da saliva, o pH salivar e a proteína total da saliva foram avaliados. Também foi verificado o valor do malondialdeído para determinação do estresse oxidativo e o total antioxidante. Resultados A quantidade de biofilme foi menor nas crianças, com erosão dentária média±desvio padrão (0,76±0,25) comparadas àquelas sem erosão dentária (1,18±0,28). Não houve diferença estatística nos parâmetros salivares de estresse oxidativo em crianças com erosão dentária. Conclusão A ação do estresse oxidativo na saliva não influenciou na erosão dentária, quando ainda nos estágios iniciais.

Effect of mouthrinses with different active agents in the prevention of initial dental erosion.

Introduction: Hydrochloric acid (HCl) from the gastric juice is the only source of intrinsic acid, which can reach the oral cavity in cases of gastroesophageal reflux or chronic vomiting, enhancing the risk of dental erosion. Aim: Compare the effects of mouthrinses with different active agents in the prevention of initial dental erosion caused by HCl. Subjects and Methods: Casein (CAS at 0.2%), sodium hexametaphosphate (HMP at 0.02%), titanium tetrafluoride (TiF4 at 0.34%), and stannous fluoride (SnF2 at 0.87%) were individually added to an experimental mouthrinse. The mouthrinse without additives was used as the negative control (C) and a commercially available mouthrinse for erosion (ELM – Elmex®) as the reference product. Enamel specimens were exposed to human saliva and randomly assigned to 6 experimental groups (n = 8). Specimens were submitted to erosion in HCl for 10 s, followed by to the experimental mouthrinses for 30 s, and artificial saliva for 60 min. This cycle was repeated 3 times. The total amounts of calcium and phosphorus released by the specimens in the 2nd and 3rd erosive challenges were evaluated by atomic emission spectrometry. Statistical analysis used Shapiro–Wilks and Hartley tests, followed by one‑way ANOVA and Tukey tests. Results: When compared with C, ELM and HMP presented significantly less calcium in solution, with no difference between them. All the groups showed similar and significantly less phosphorus than C, except CAS. Conclusions: HMP was the only agent that could match the protection against initial erosion of the commercially available mouthrinse in both analyses.

Diabetes: noções gerais para o Cirurgião-Dentista / Diabetes: general characteristics for dentists

Diabetes mellitus é uma enfermidade crônica de origem endocrinológica e que afeta mais de 170 milhões de pessoas no mundo e possui como principal característica a hiperglicemia. Na Odontologia, alguns estudos mostram que os pacientes diabéticos descompensados reportam algumas alterações na cavidade oral, relacionadas com o estado hiperglicêmico, como por exemplo, xerostomia e hipossalivação, aumento nos índices de cárie e doença periodontal e alteração na reparação tecidual. Com isto, este trabalho tem o objetivo de levar aos cirurgiões dentistas conceitos, características da doença, complicações orais relacionadas com o Diabetes mellitus e algumas opções de terapias para estas complicações orais, como a laserterapia e a terapia fotodinâmica antimicrobiana.

Diabetes mellitus consists of a group of metabolic diseases characterized by hyperglycemia, resulting from disorders in insulin secretion, insulin action or both. A higher incidence of oral diseases, related to poorly controlled diabetes, can be observed in diabetic patients, such as xerostomia, hyposalivation, higher risk of infection, carious lesions, taste alterations, in addition to inadequate preparation of food for digestion. Thus, the aim of this study was to get some important information about this disease, for dentistis, as well as some therapeutic options for oral complications, suh as lasertherapy and antimicrobial photodynamic therapy.

Porosity, residual monomer and water sorption of conventional heat-cured, microwave-cured and cross-linked acrylic resins

This study compared the residual monomer release, water sorption and superfi cial porosity of different resins commonly employed in eye prostheses: heat-cured (HC); microwave-cured (MC) and self-curing cross-linked acrylic resins (SC). Four groups were established: G1, HC / water bath cycle; G2, MC / microwave cycle; G3, HC / microwave cycle; G4, SC. The amount of residual monomer was similar in G1 and G3, lower in G2 and higher in G4. Water sorption was similar in all groups. G2 showed more superfi cial porosity, and G1 and G3 were similar in this regard. Neither the conventional heat-curing cycle nor the microwave cycle affected the amount of residual monomer or porosity of the conventional heat-cured acrylic resin. Water sorption was not affected by the type of resin or polymerization cycle used. Residual monomer release and porosity were related to the type of resin employed rather than the polymerization cycle they were submitted to.

Activity, distribution and regulation of phosphofructokinase in salivary gland of rats with streptozotocin-induced diabetes

Apesar de existirem muitos estudos sobre a influência do diabetes nas glândulas salivares, esses apresentam resultados conflitantes. Neste estudo, a regulação da enzima fosfofrutoquinase-1 (PFK-1) foi estudada utilizando-se glândulas salivares de ratos. O diabetes foi induzido por uma única injeção intraperitonial de estreptozotocina (60 mg/kg peso corporal) em ratos (180-200 g). Os animais foram sacrificados 30 dias após a indução do diabetes e utilizaram-se as glândulas submandibular e parótida. A hiperglicemia foi avaliada por determinação da glicemia sanguínea. A distribuição da PFK-1 entre frações solúvel e ligada, concentração de fosfato na PFK-1, concentração de frutose-2,6-bisfosfato e a atividade da enzima PFK-2 foram determinadas. O cálculo do peso glandular relativo mostrou um aumento na glândula parótida de ratos diabéticos comparados ao controle, o que não ocorreu na glândula submandibular. A atividade da PFK-1 expressa por glândula não mostrou variação entre animais diabético e controle. Contudo, considerando a atividade específica, a fração solúvel da enzima mostrou aumento de 50% com relação ao controle e a fração ligada ao citoesqueleto um aumento de 84% com relação ao controle. Na glândula parótida não foi observada diferença na atividade específica entre os grupos diabético e controle. Por outro lado, a atividade por glândula da fração solúvel aumentou nos animais diabéticos. A concentração de fosfato da PFK-1 aumentou nas glândulas submandibular e parótida nos animais diabéticos. Tanto a concentração de frutose-2,6-bisfosfato quanto a forma ativa da PFK-2 mostraram redução nas glândulas salivares. Concluindo, o aumento na atividade da PFK-1 observado nas glândulas salivares de ratos com diabetes induzida por estreptozotocina não parece ser modulado pela frutose-2,6-bisfosfato.