CYP450 polymorphisms and clinical pharmacogenetics of ibuprofen after lower third molar extraction.

PURPOSE: This study hypothesized that drugs accumulate in the bloodstream of poor-metabolizing patients and may have more adverse effects and different pain perceptions and aimed to investigate the influence of CYP450 polymorphisms on acute postoperative pain, swelling, and trismus controlled by ibuprofen (600 mg) in 200 volunteers after dental extraction. In addition, surgical outcomes can determine pain, edema, and trismus and indicate inflammatory reactions after oral surgeries. METHODS: Genetic sequencing was performed to identify CYP450 polymorphisms and the surgical parameters evaluated: pre and postoperative swelling, trismus, and temperature; self-reported postoperative pain with visual analog scale (VAS); rescue medication consumed; and severity of adverse reactions. RESULTS: A multiple linear regression model with independent variables [single nucleotide polymorphisms (SNPs), BMI (body mass index), duration, and difficulty of surgery] and dependent variables [postoperative pain by sum of pain intensity difference (SPID), trismus, and swelling] was used for analysis. The duration of surgery was a predictor for pain at 8 h and 96 h after surgery, and BMI was a predictor for both swelling and trismus on the 2nd postoperative day. When evaluating CYP2C8 and C9 genotyped SNPs, it was observed that normal metabolizers showed higher pain levels than the intermediate/poor metabolizers on the postoperative periods as compared with time 0 h. In another analysis, the poor metabolizers for CYP2C8 and C9 presented lower levels of postoperative pain after 8 h and used rescue medication earlier than normal metabolizers. CONCLUSION: Ibuprofen 600 mg was very effective in controlling inflammatory pain after lower third molar surgeries, without relevant adverse reactions; although in a very subtle way, patients with poor metabolism had higher levels of pain in the first hours, and no longer after 8 h, and used pain relief medication earlier. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov ID (NCT03169127), on March 16th, 2017.

Dexamethasone Does Not Inhibit Treadmill Training-Induced Angiogenesis in Myocardium: Role of MicroRNA-126 Pathway.

Dexamethasone (DEX) has important anti-inflammatory activities; however, it induces hypertension and skeletal muscle microcirculation rarefaction. Nevertheless, nothing is known about DEX outcomes on cardiac microcirculation. By contrast, exercise training prevents skeletal and cardiac microvessel loss because of microRNA expression and a better balance between their related angiogenic and apoptotic proteins in spontaneously hypertensive rats. The purpose of this study was to investigate whether DEX and/or exercise training could induce microRNA alterations leading to cardiac angiogenesis or microvascular rarefaction. Animals performed 8 weeks of exercise training and were treated with DEX (50 µg/kg per day, subcutaneously) for 14 days. Cardiovascular parameters were measured, and the left ventricle muscle was collected for analyses. DEX treatment increased arterial pressure and did not cause cardiac microcirculation rarefaction. Treadmill training prevented the DEX-induced increase in arterial pressure. In addition, training, regardless of DEX treatment, increased microRNA-126 expression, phospho-protein kinase B/protein kinase B, and endothelial nitric oxide synthase levels associated with cardiac angiogenesis. In conclusion, this study suggests, for the first time, that treadmill training induces myocardial angiogenesis because of angiogenic pathway improvement associated with an increase in microRNA-126. Furthermore, DEX, per se, did not cause capillary density alterations and did not attenuate cardiac angiogenesis induced by training.

Novel rare variations in IRF6 in subjects with non-syndromic cleft lip and palate and dental agenesis.

OBJECTIVE: Subjects with cleft lip and palate (CLP) present high prevalence of dental agenesis. Among candidate genes for these phenotypes is IRF6. However, genetic studies do not analyze dental agenesis as a phenotype associated with cleft. Therefore, we investigated the frequency of rare and novel variations in IRF6 in subjects with non-syndromic unilateral cleft lip and palate (NSUCLP), with and without dental agenesis. SUBJECTS AND METHODS: Genomic DNA samples of 100 subjects with NSUCLP with and without dental agenesis and 50 controls were sequenced. IRF6 mutational screening was conducted by direct sequencing. RESULTS: Ten new and rare missense variations were identified, two in the group cleft with agenesis and eight in the group cleft without agenesis, and none were found in control group. In silico analysis revealed four variations as potentially deleterious, being two in the group with cleft and agenesis and two in the group with cleft without agenesis. CONCLUSION: The study identified novel IFR6 variations in subjects with NSUCLP with or without associated dental agenesis. The hypothesis of a higher frequency of deleterious variations in the subjects with cleft associated with dental agenesis, when compared to the group of cleft without agenesis and control without cleft, was not supported.

Analysis of Polymorphisms in Genes Differentially Expressed in the Enamel of Mice with Different Genetic Susceptibilities to Dental Fluorosis.

Genes expressed during amelogenesis are candidates to increase the risk of dental fluorosis (DF). Thus, this study aimed to evaluate the association between polymorphisms in enamel development genes and susceptibility to DF in mice. Mice of both sexes, representing strains 129P3/J (n = 20; resistant to DF) and A/J (n = 20; susceptible to DF), were divided into 2 groups. Each strain received a diet with a low concentration of fluoride (F) and drinking water containing 0 or 50 mg/L of F for 6 weeks. Clinical evaluation and analysis of Vickers enamel microhardness of the incisors were performed. Livers were collected for genomic DNA extraction. Seventeen genetic polymorphisms in Amelx, Ambn, Ambn, Col14a1, Col1a1, Col5a2, Enam, Fam20a, Fam83h, Foxo1, Klk4, Mmp20, Serpinf1, Serpinh1, Smad3, Tuft1, and Wdr72 were genotyped by real-time PCR using Taqman chemistry. Overrepresentation of alleles and genotypes in DF was evaluated using the χ2 test with an alpha of 5%. The clinical aspects of the enamel and the surface enamel microhardness confirmed the DF condition. In the polymorphisms rs29569969, rs13482592, and rs13480057 in Ambn, Col14a1, and Mmp20, respectively, genotype and allele distributions were statistically significantly different between A/J and 129P3/J strains (p < 0.05). In conclusion, polymorphisms in Ambn, Col14a1, and Mmp20 are associated with the susceptibility to DF.

CCR5Δ32 (rs333) polymorphism is associated with decreased risk of chronic and aggressive periodontitis: A case-control analysis based in disease resistance and susceptibility phenotypes.

Chronic and aggressive periodontitis are infectious diseases characterized by the irreversible destruction of periodontal tissues, which is mediated by the host inflammatory immune response triggered by periodontal infection. The chemokine receptor CCR5 play an important role in disease pathogenesis, contributing to pro-inflammatory response and osteoclastogenesis. CCR5Δ32 (rs333) is a loss-of-function mutation in the CCR5 gene, which can potentially modulate the host response and, consequently periodontitis outcome. Thus, we investigated the effect of the CCR5Δ32 mutation over the risk to suffer periodontitis in a cohort of Brazilian patients (total N=699), representative of disease susceptibility (chronic periodontitis, N=197; and aggressive periodontitis, N=91) or resistance (chronic gingivitis, N=193) phenotypes, and healthy subjects (N=218). Additionally, we assayed the influence of CCR5Δ32 in the expression of the biomarkers TNFα, IL-1ß, IL-10, IL-6, IFN-γ and T-bet, and key periodontal pathogens P. gingivalis, T. forsythia, and T. denticola. In the association analysis of resistant versus susceptible subjects, CCR5Δ32 mutant allele-carriers proved significantly protected against chronic (OR 0.49; 95% CI 0.29-0.83; p-value 0.01) and aggressive (OR 0.46; 95% CI 0.22-0.94; p-value 0.03) periodontitis. Further, heterozygous subjects exhibited significantly decreased expression of TNFα in periodontal tissues, pointing to a functional effect of the mutation in periodontal tissues during the progression of the disease. Conversely, no significant changes were observed in the presence or quantity of the periodontal pathogens P. gingivalis, T. forsythia, and T. denticola in the subgingival biofilm that could be attributable to the mutant genotype.

Exercise Training Prevents Dexamethasone-induced Rarefaction.

Dexamethasone (DEX) causes rarefaction. In contrast, training (T) prevents rarefaction and stimulates angiogenesis. This study investigated the mechanisms responsible for the preventive role of T in DEX-induced rarefaction. Rats underwent T or were kept sedentary (8 weeks) and were treated with DEX or saline during the following 14 days. Tibialis anterior muscle was used for measurements of capillary density (CD), capillary-to-fiber ratio (C:F ratio), superoxide dismutase CuZn (SOD-1), superoxide dismutase MnSOD (SOD-2), catalase (CAT) mRNA as well as SOD-1, SOD-2, CAT, vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-2 (VEGF-R2), cyclooxygenase-2 (COX-2), B-cell lymphoma 2 (Bcl-2), Bd-2-like protein 4 (Bax), p-Bax, and caspase-3 cleaved protein levels. DEX decreased CD (-38.1%), C:F ratio (-30.0%), VEGF (-19.0%), VEGFR-2 (-20.1%), COX-2 (-22.8%), Bcl-2 (-20.5%), Bcl-2/Bax ratio (-13.7%), p-Bax/Bax (-20.0%) and increased SOD-2 (+41.6%) and caspase-3 cleaved (+24.1%). Conversely, T prevented reductions in CD (+54.2%), C:F ratio (+32.9%), VEGF (+25.3%), VEGFR-2 (+22.2%), COX-2 (+31.5%), Bcl-2 (+35.5%), Bcl-2/Bax ratio (+19.9%), p-Bax/Bax (+32.1%), and caspase-3 cleaved increase (-7.8%). T increased CAT mRNA (+21.5%) in the DEX-treated group. In conclusion, T prevented the DEX-induced rarefaction by increasing antioxidant enzymes resulting in a better balance between apoptotic and anti-apoptotic protein levels.

Comparison of epinephrine and felypressin pressure effects in 1K1C hypertensive rats treated or not with atenolol.

PURPOSE: Epinephrine is considered the gold standard vasoconstrictor for hypertensive patients, but few studies report felypressin's effects. The present study aimed to analyze and compare the effects of these two vasoconstrictors, injected by the intravenous route, on the arterial pressure of normotensive, hypertensive and atenolol-treated hypertensive rats. METHOD: The hypertension model was one-kidney-one-clip (1K1C): the main left renal artery was partially constricted and the right kidney was surgically removed in 45-day-old male Wistar rats. 1K1C hypertensive rats received atenolol (90 mg/kg/day) by gavage for 2 weeks. 28-35 days after hypertension induction, a catheter was inserted into the left carotid artery to record direct blood pressure values. The following parameters were recorded: minimal hypotensive response, maximal hypertensive response, response duration and heart rate. RESULTS: Epinephrine, but not felypressin, exerted an important hypotensive action; non-treated hypertensive rats showed more pronounced vasodilation. Treated and non-treated rats showed hypertensive responses of the same magnitudes in all groups; 1K1C atenolol rats showed reduced hypertensive responses to both vasoconstrictors. Felypressin's response duration was longer than that of epinephrine in all groups. Epinephrine increased heart rate while felypressin reduced this parameter only in the normotensive group. CONCLUSIONS: Our results suggest that felypressin has equipotent pressure responses when compared with epinephrine, showing a greater extent of action. Atenolol's reduction of hypertensive effects surprisingly suggests that atenolol ß-blockade may also be important for felypressin's cardiovascular effect, as is widely known for epinephrine. Our data suggest that felypressin is safe for hypertensive subjects, in particular those receiving atenolol.

Blockade of Inflammatory Markers Attenuates Cardiac Remodeling and Fibrosis in Rats with Supravalvular Aortic Stenosis.

Since cardiac inflammation has been considered an important mechanism involved in heart failure, an anti-inflammatory treatment could control cardiac inflammation and mitigate the worsening of cardiac remodeling. This study evaluated the effects of dexamethasone (DEX) and ramipril treatment on inflammation and cardiac fibrosis in an experimental model of heart failure induced by supravalvular aortic stenosis. Wistar rats (21d) were submitted to an aortic stenosis (AS) protocol. After 21 weeks, an echocardiogram and a maximal exercise test were performed, and after 24 weeks, rats were treated with DEX, ramipril or saline for 14d. The left ventricle (LV) was removed for histological and inflammatory marker analyses. The AS group showed exercise intolerance (-32% vs. Sham), higher relative wall thickness (+63%), collagen deposition and capillary rarefaction, followed by cardiac disfunction. Both treatments were effective in reducing cardiac inflammation, but only DEX attenuated the increased relative wall thickness (-17%) and only ramipril reduced LV fibrosis. In conclusion, both DEX and ramipril decreased cardiac inflammatory markers, which probably contributed to the reduced cardiac fibrosis and relative wall thickness; however, treated AS rats did not show any improvement in cardiac function. Despite the complex pharmacological treatment of heart failure, treatment with an anti-inflammatory could delay the patient's poor prognosis.

Angiotensin II Regulates Proliferation and Function of Stem Cells of Apical Papilla.

INTRODUCTION: Stem cells of apical papilla (SCAP) may be affected by inflammatory mediators released by activation with lipopolysaccharide (LPS) from infected pulpal cavities of necrotic immature teeth. Therefore, this study aimed to investigate the presence of a local renin-angiotensin system (RAS) and the role of angiotensin II (Ang II) on the modulation of SCAP in vitro. METHODS: Primary cultures of SCAP were incubated with LPS (0.1-10 µg/mL) for cell viability and quantification of the chemokine CCL2. Components of RAS were searched by gene expression of angiotensinogen (AGTN), angiotensin converting enzyme (ACE), renin, angiotensin receptor 1 (AT1) and 2 (AT2), and Mas receptor. Ang II was investigated in SCAP supernatants. Immunofluorescence was used to detect AGTN and AT1. Next, cells were treated with Ang II for viability/proliferation assessment, quantification of CCL2 and interleukin 6, and mineralization assay. Data were evaluated by analysis of variance using Tukey post hoc comparisons or the Student t test. P values <.05 were considered to be significant. RESULTS: LPS increased CCL2 production at 1 and 10 µg/mL. The gene expression of AGTN, renin, ACE, and AT1 was detected, but only ACE was increased by LPS. Ang II peptide was found in SCAP supernatants but unaltered by LPS. Both AGTN and AT1 proteins were detected by immunostaining. Ang II significantly induced SCAP proliferation, increased CCL2 production, down-regulated IL-6 release, and reduced the SCAP mineralization rate. CONCLUSIONS: A local RAS was found at the apical papilla, and Ang II was able to modulate SCAP function in vitro.

MicroRNA-126 upregulation, induced by training, plays a role in controlling microcirculation in dexamethasone treated rats.

Microcirculation maintenance is associated with microRNAs. Nevertheless, the role of microRNAs induced by training in preventing dexamethasone (DEX)-induced microvascular rarefaction remains unknown. The study aim was to investigate if training-induced microRNAs are able to improve microcirculation proteins and prevent DEX-induced microvascular rarefaction. Rats underwent training for 8 weeks and then were treated with DEX (50 µg/kg per day, s.c.) for 14 days. Arterial pressure was measured and tibialis anterior (TA) muscle was collected for analyses. DEX induced hypertension concomitantly with capillary density loss (CD, -23.9%) and decrease of VEGF (-43.0%), p-AKT/AKT (-39.6%) and Bcl-2 (-23.0%) and an increase in caspase-3-cleaved protein level (+34.0%) in TA muscle. Training upregulated microRNA-126 expression (+13.1%), prevented VEGF (+61.4%), p-AKT/AKT (+37.7%), Bcl-2 (+7.7%) decrease and caspase-3-cleaved (-23.1%) increase associated with CD (+54.7%) reduction and hypertension prevention. MiRNA-126 upregulation, induced by training, plays a role in controlling microcirculation, which may be a potential target against DEX-induced microvascular rarefaction.

Passive Cigarette Smoking Impact on Blood Pressure Response to Epinephrine and Felypressin in 1K1C Hypertensive Rats Treated or not with Atenolol.

BACKGROUND: Cigarette smoking is usually associated with hypertension and may modify vasoconstrictor response. OBJECTIVE: The present study aimed to analyze and compare the interaction of passive cigarette smoking and hypertension on epinephrine and felypressin blood pressure effects after intravascular injection. METHOD: 45-day male Wistar rats had the main left renal artery partially constricted and the right kidney removed (1K1C model). Rats were placed in the chamber for exposition to passive cigarette smoking (10 cigarettes) during 10 min (6 days a week). Hypertensive rats received atenolol (90 mg/kg/day) by gavage for two weeks. Hypotensive and hypertensive response, response duration and heart rate were recorded from direct blood pressure values. The significance level was 5%. RESULTS: Passive cigarette smoking increased maximal hypertensive response to epinephrine in normotensive and 1K1C-atenolol treated rats and to felypressin only in 1K1C-atenolol treated rats; it also reduced epinephrine hypotensive response. Epinephrine increased heart rate in normotensive and hypertensive passive smokers or non-smoker rats. Comparing the two vasoconstrictors, epinephrine showed greater hypertensive response in normotensive smokers, 1K1C-atenolol treated smokers and non-smokers. However, in normotensive-nonsmoker rats, felypressin showed a greater and longer hypertensive effect. CONCLUSIONS: Our results suggest that passive cigarette smoking may reduce epinephrine vasodilation and increase hypertensive response when compared to felypressin. Therefore, felypressin may be safe for hypertensive patients to avoid tachycardia and atenolol interaction, but for normotensive and non-smoker patients, epinephrine may be safer than felypressin.

AT1 receptor antagonism promotes bone loss attenuation in experimental periodontitis, blocks inflammatory mediators, and upregulates antioxidant enzymes and bone formation markers.

BACKGROUND: The initiation and progression of periodontitis might involve a local renin-angiotensin system in periodontal tissue. This study hypothesized that Losartan treatment could promote protection to rats submitted to experimental periodontitis (EP) by attenuating alveolar bone loss due to reduction in inflammatory cytokines, better reactive oxidant species regulation and maintenance of the balance between bone formation and resorption factors. METHODS: One hundred and thirty rats were submitted to EP with a silk suture thread (4.0) placed around the lower right first molar for 1, 3, 7, and 14 consecutive days. The study comprised four groups: G1-control without EP; G2-animals with EP treated with water; G3-Losartan-treated animals (treatment started at the same day of EP induction), and G4-animals previously treated with Losartan for 30 days followed by induction of EP and continuity of treatment. RESULTS: G2 rats had greater bone loss volume, increased number, and thickness and decreased separation of trabeculae. On the other hand, G4 animals showed significant improvements in these parameters. Histological analysis revealed that EP favors inflammatory cell infiltration and junctional epithelium, cementum with alveolar bone crest destruction, but animals pretreated with Losartan (G4) did not show these features. Although the G3 animals did not demonstrate the improvements detected in G4, mRNA expression results were similar. In mandibular tissue, EP promoted mRNA increases for ACE, AT1 receptor, and inflammatory mediators as well as decreases for antioxidant enzymes. However, Losartan treatments attenuated these responses in addition to promoting an increase in bone formation markers and transcription factors. CONCLUSION: AT1 receptor modulates EP progression.

COX-2 inhibition decreases VEGF expression and alveolar bone loss during the progression of experimental periodontitis in rats.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a macromolecule of importance in inflammation that has been implicated in periodontitis. The aims of this study were to investigate VEGF expression during the progression of periodontal disease and to evaluate the effect of a preferential cyclooxygenase (COX)-2 inhibitor meloxicam on VEGF expression and alveolar bone loss in experimentally induced periodontitis. METHODS: A total of 120 Wistar rats were randomly separated into groups 1 (control) and 2 (meloxicam, 3 mg/kg/day, intraperitoneally, for 3, 7, 14, or 30 days). Silk ligatures were placed at the gingival margin level of the lower right first molar of all rats. VEGF expression was assessed by reverse transcription-polymerase chain reaction (RT-PCR), Western blot (WB), and immunohistochemical (IHC) analyses. The hemiarcades were processed for histopathologic analysis. RT-PCR and WB results were submitted to analysis of variance, the Tukey test, and Pearson correlation analysis (P <0.05). RESULTS: A reduction in alveolar bone resorption was observed in the meloxicam-treated group compared to the control group at all periods studied. There was a positive correlation between COX-2 mRNA and VEGF mRNA in the gingival tissues and periodontal disease (R = 0.80; P = 0.026). Meloxicam significantly reduced the increased mRNA VEGF expression in diseased tissues after 14 days of treatment (P = 0.023). Some alterations in VEGF receptor 1 mRNA expression were observed, but these were not statistically significant. VEGF protein expression in WB experiments was significantly higher in diseased sites compared to healthy sites (P <0.05). After 14 days of treatment with meloxicam, an important decrease in VEGF protein expression was detected in diseased tissues (P = 0.08). Qualitative IHC analysis revealed that VEGF protein expression was higher in diseased tissues and decreased in tissues from rats treated with meloxicam. CONCLUSIONS: The present data suggest an important role for VEGF in the progression of periodontal disease. Systemic therapy with meloxicam can modify the progression of experimentally induced periodontitis in rats by reducing VEGF expression and alveolar bone loss.

Short-term exposure to dexamethasone promotes autonomic imbalance to the heart before hypertension.

Hypertension is one of the chronic side effects of dexamethasone (DEX) treatment; however, almost nothing is known about its acute effects. Therefore, the aim of this study was to investigate the possible mechanisms involved in blood pressure control after acute or short-term DEX treatment in adult animals. Eighty Wistar rats were divided into four groups: C1 and C5, for rats treated with saline for 1 or 5 days, respectively; D1 and D5, for rats treated with DEX for 1 or 5 days, respectively (decadron, 1 mg/kg, i.p.). Heart rate was increased in DEX treatment, but arterial pressure and cardiac muscle mass were not altered. Only few and isolated changes on gene expression and protein level of renin-angiotensin system components were observed. Five days of DEX treatment, but not one day, determined an increase in sympathetic component of spectral analysis (+75.93%, P < .05) and a significant reduction of parasympathetic component (-18.02%, P < .05), which contributed to the autonomic imbalance to the heart (LF/HF, +863.69%). The results of this present study demonstrated, for the first time, that short-term exposure to DEX treatment impairs the autonomic balance to the heart before hypertension, which was independent of renin-angiotensin system.

Epinephrine concentration (1:100,000 or 1:200,000) does not affect the clinical efficacy of 4% articaine for lower third molar removal: a double-blind, randomized, crossover study.

PURPOSE: This study compared the use of 4% articaine in association with 1:100,000 (10 mug/mL; A100) or 1:200,000 (5 mug/mL; A200) epinephrine in lower third molar removal. PATIENTS AND METHODS: Fifty healthy volunteers underwent removal of symmetrically positioned lower third molars, in 2 separate appointments, under local anesthesia with either A100 or A200, in a double-blind, randomized, and crossed manner. Latency, duration of postoperative analgesia, duration of anesthetic action on soft tissues, intraoperative bleeding, and hemodynamic parameters were evaluated. RESULTS: A100 and A200 presented very similar latency (1.64 +/- 0.08 and 1.58 +/- 0.08 minutes, respectively; P > .05). Identical volumes of both anesthetic solutions were used: 2.7 mL = 108 mg of articaine plus 27 mug (A100) or 13.5 mug (A200) of epinephrine. The 2 solutions provided similar duration of postoperative analgesia regardless of bone removal (around 200 minutes; P > .05). The 2 solutions also had a similar duration of anesthetic action on soft tissues (around 250 minutes; P > .05). The surgeon's rating of intraoperative bleeding was considered very close to minimal. Transient changes in hemodynamic parameters were observed, but these were neither clinically significant nor attributable to the type of anesthetic used (P > .05). CONCLUSIONS: An epinephrine concentration of 1:100,000 or 1:200,000 in 4% articaine solution does not affect the clinical efficacy of this local anesthetic. It is possible to successfully use the 4% articaine formulation with a lower concentration of epinephrine (1:200,000 or 5 mug/mL) for lower third molar extraction with or without bone removal.

Exercise attenuates dexamethasone-induced hypertension through an improvement of baroreflex activity independently of the renin-angiotensin system.

Dexamethasone-induced hypertension may be caused by baroreflex alterations or renin-angiotensin system (RAS) exacerbation. Aerobic training has been recommended for hypertension treatment, but the mechanisms responsible for reduction of arterial pressure (AP) in dexamethasone (DEX) treated rats are still inconclusive.This study evaluated whether mechanisms responsible for training-induced attenuation of hypertension involve changes in autonomic nervous system and in RAS components. Rats underwent aerobic training protocol on treadmill or were kept sedentary for 8 weeks. Additionally, animals were treated with DEX during the last 10 days of exercise. Body weight (BW), AP and baroreflex activity were analyzed. Tibialis anterior (TA), soleus (SOL) and left ventricle (LV) were collected for evaluation of RAS components gene expression and protein levels. Dexamethasone decreased BW (20%), caused TA atrophy (16%) and increased systolic AP (SAP, 16%) as well as decreased baroreflex activity. Training attenuated SAP increase and improved baroreflex activity, although it did not prevent DEX-induced BW reduction and muscle atrophy. Neither DEX nor training caused expressive changes in RAS components. In conclusion, exercise training was effective in attenuating hypertension induced by DEX and this response may be mediated by a better autonomic balance through an improvement of baroreflex activity rather than changes in RAS components.

Exercise training attenuates dexamethasone-induced hypertension by improving autonomic balance to the heart, sympathetic vascular modulation and skeletal muscle microcirculation.

OBJECTIVE: Although aerobic exercise training has been recommended as nonpharmacological treatment of high blood pressure, the mechanisms of training-induced blood pressure lowering effects in dexamethasone (DEX)-induced hypertension remain unclear. Therefore, the aim of this study was to investigate the preventive role of exercise training in counteracting DEX-induced hypertension. METHODS: Rats were submitted to aerobic exercise training for 8 weeks or kept sedentary and then treated with DEX (50 µg/kg/day, s.c.) or saline injections for 14 days. Thereafter, all rats underwent carotid artery catheterization, and cardiovascular autonomic modulation was evaluated by spectral analysis. In addition, soleus muscle was collected for morphometric and protein level analysis. RESULTS: DEX treatment increased arterial pressure concomitantly with an increase in low-frequency spectral power of systolic arterial pressure and low frequency in pulse interval (94.11 and 58.58%, respectively), and a decrease in high-frequency spectral power of pulse interval (-12.05%). Capillary density (-25.87%), capillary-to-fibers ratio (-21.22%), vascular endothelial growth factor level (-15.10%), B-cell lymphoma 2 (Bcl-2) level (-16.40%) and Bcl-2/Bcl-2 associated X protein ratio (-27.14%) were all decreased after DEX treatment. Exercise training attenuated DEX-induced increase in arterial pressure accompanied by an attenuation of low-frequency spectral power of systolic arterial pressure, low frequency in pulse interval increases and high-frequency spectral power of pulse interval decrease. Training also prevented the decrease in capillary density (+44.43%), capillary-to-fibers ratio (+36.97%), vascular endothelial growth factor (+16.46%), Bcl-2 (+15.21%) protein level and Bcl-2/Bcl-2-associated X protein ratio (+30.93%). CONCLUSION: These results demonstrate that exercise training improves cardiovascular autonomic balance to the heart associated with an improvement in sympathetic modulation of vascular tone and microcirculatory function in the skeletal muscle of DEX-induced hypertensive rats.

Passive Cigarette Smoking Impact on Blood Pressure Response to Epinephrine and Felypressin in 1K1C Hypertensive Rats Treated or not with Atenolol / Impacto do Tabagismo Passivo na Resposta Pressórica à Epinefrina e Felipressina em Ratos Hipertensos 1K1C Tratados ou não com Atenolol

Abstract Background: Cigarette smoking is usually associated with hypertension and may modify vasoconstrictor response. Objective: The present study aimed to analyze and compare the interaction of passive cigarette smoking and hypertension on epinephrine and felypressin blood pressure effects after intravascular injection. Method: 45-day male Wistar rats had the main left renal artery partially constricted and the right kidney removed (1K1C model). Rats were placed in the chamber for exposition to passive cigarette smoking (10 cigarettes) during 10 min (6 days a week). Hypertensive rats received atenolol (90 mg/kg/day) by gavage for two weeks. Hypotensive and hypertensive response, response duration and heart rate were recorded from direct blood pressure values. The significance level was 5%. Results: Passive cigarette smoking increased maximal hypertensive response to epinephrine in normotensive and 1K1C-atenolol treated rats and to felypressin only in 1K1C-atenolol treated rats; it also reduced epinephrine hypotensive response. Epinephrine increased heart rate in normotensive and hypertensive passive smokers or non-smoker rats. Comparing the two vasoconstrictors, epinephrine showed greater hypertensive response in normotensive smokers, 1K1C-atenolol treated smokers and non-smokers. However, in normotensive-nonsmoker rats, felypressin showed a greater and longer hypertensive effect. Conclusions: Our results suggest that passive cigarette smoking may reduce epinephrine vasodilation and increase hypertensive response when compared to felypressin. Therefore, felypressin may be safe for hypertensive patients to avoid tachycardia and atenolol interaction, but for normotensive and non-smoker patients, epinephrine may be safer than felypressin.

Resumo Fundamento: O tabagismo geralmente está associado à hipertensão e pode modificar a resposta vasoconstritora. Objetivo: O presente estudo teve como objetivo analisar e comparar a interação do tabagismo passivo e hipertensão sobre os efeitos da epinefrina e felipressina na pressão arterial após injeção intravascular. Métodos: Ratos Wistar machos de 45 dias tiveram a artéria renal principal esquerda parcialmente obstruída e o rim direito removido (modelo 1K1C). Os ratos foram colocados na câmara para exposição ao tabagismo passivo (10 cigarros) durante 10 minutos (6 dias por semana). Ratos hipertensos receberam atenolol (90 mg/kg/dia) por gavagem durante duas semanas. A resposta hipotensora e hipertensiva, a duração da resposta e a frequência cardíaca foram registradas a partir da medida dos valores diretos da pressão arterial. O nível de significância foi de 5%. Resultados: O tabagismo passivo aumentou a resposta hipertensiva máxima à epinefrina em ratos normotensos e ratos 1K1C tratados com atenolol e à felipressina apenas em ratos 1K1C tratados com atenolol; também reduziu a resposta hipotensiva à epinefrina. A epinefrina aumentou a frequência cardíaca em ratos fumantes passivos ou não-fumantes, normotensos e hipertensos. Comparando os dois vasoconstritores, a epinefrina apresentou maior resposta hipertensiva em fumantes normotensos, ratos 1K1C fumantes e não fumantes tratados com atenolol. No entanto, em ratos normotensos e não fumantes, a felipressina apresentou um efeito hipertensivo maior e mais prolongado. Conclusões: Nossos resultados sugerem que o tabagismo passivo pode reduzir a vasodilatação da epinefrina e aumentar a resposta hipertensiva quando comparado à felipressina. Portanto, a felipressina pode ser segura para pacientes hipertensos, com o objetivo de evitar a interação entre taquicardia e atenolol, mas para pacientes normotensos e não-fumantes, a epinefrina pode ser mais segura que a felipressina.

Functional Local Renin-Angiotensin System in Human and Rat Periodontal Tissue.

The initiation or progression of periodontitis might involve a local renin-angiotensin system (RAS) in periodontal tissue. The aim of this study was to further characterize the local RAS in human and rat periodontal tissues between healthy and periodontally-affected tissue. Components of the RAS were investigated using in vitro, ex vivo and in vivo experiments involving both human and Wistar rat periodontium. Although not upregulated when challenged with P. gingivalis-lipopolysaccharide, human gingival and periodontal ligament fibroblasts expressed RAS components. Likewise, healthy and inflamed human gingiva expressed RAS components, some of which were shown to be functional, yet no differences in expression were found between healthy and diseased gingiva. However, in inflamed tissue the immunoreactivity was greater for the AT1R compared to AT2R in fibroblasts. When compared to healthy tissue, ACE activity was increased in human gingiva from volunteers with gingivitis. Human-gingiva homogenates generated Ang II, Ang 1-9 and Ang 1-7 when incubated with precursors. In gingiva homogenates, Ang II formation from Ang I was nearly abolished only when captopril and chymostatin were combined. Ang 1-7 formation was significantly greater when human gingiva homogenates were incubated with chymostatin alone compared to incubation without any inhibitor, only captopril, or captopril and chymostatin. In rat gingiva, RAS components were also found; their expression was not different between healthy and experimentally induced periodontitis (EP) groups. However, renin inhibition (aliskiren) and an AT1R antagonist (losartan) significantly blocked EP-alveolar-bone loss in rats. Collectively, these data are consistent with the hypothesis that a local RAS system is not only present but is also functional in both human and rat periodontal tissue. Furthermore, blocking AT1R and renin can significantly prevent periodontal bone loss induced by EP in rats.

MicroRNA-146a and microRNA-155 show tissue-dependent expression in dental pulp, gingival and periodontal ligament fibroblasts in vitro.

MicroRNAs (miRNAs) are small non-coding RNAs showing a tissue-specific expression pattern, and whose function is to suppress protein synthesis. In this study, we hypothesized that expression of miRNAs would differ among fibroblasts from dental pulp (DPF), gingiva (GF) and periodontal ligament (PLF) in vitro. Once established by an explant technique, DPF, GF and PLF were collected for RNA isolation and subjected to a miRNA microarray. Next, cells were stimulated with E. coli lipopolysaccharide (LPS) for 24 h and then collected for RNA isolation. Expression of miR-146a and miR-155 was investigated by qPCR. Microarray screening revealed several miRNAs that showed specifically high expression in at least one of the fibroblast subtypes. These molecules are potentially involved in the regulation of extracellular matrix turnover and production of inflammatory mediators. Microarray analysis showed that both miR-146a and miR-155 were among the miRNAs expressed exclusively in GF. qPCR demonstrated significant upregulation of miR-146a only in GF after LPS stimulation, whereas basal expression of miR-155 was higher in GF than in the other cell subtypes. LPS downregulated the expression of miR-155 only in GF. Our results suggest that the expression and regulation of miR-146a and miR-155 are more pronounced in GF than in DPF and PLF.