Pre-treatment and continuous administration of simvastatin during sepsis improve metabolic parameters and prevent CNS injuries in survivor rats.

Sepsis causes overproduction of inflammatory cytokines, organ dysfunction, and cognitive impairment in survivors. In addition to inflammation, metabolic changes occur according to the stage and severity of the disease. Understanding the role and place of metabolic disturbances in the pathophysiology of sepsis is essential to evaluate the framework of septic patients, predict the syndrome progress, and define the treatment strategies. We investigated the effect of simvastatin on the disease time course and on metabolic alterations, especially with respect to their possible consequences in the CNS of surviving rats. The animals of this study were weighed daily and followed for 10 days to determine the survival rate. In the first experiment, control or cecal ligation and puncture (CLP)-animals were randomized in 24 h, 48 h, and 10 days after septic induction, for bacterial load determination and quantification of cytokines. In the second experiment, control or CLP-animals were treated or not with simvastatin and randomized in the same three time points for cytokines quantification and assessment of their body metabolism and locomotor activity (at 48 h and 10 days), as well as the evaluation of cytoarchitecture and astrogliosis (at 10 days). The CLP-rats treated with simvastatin showed a reduction in plasma cytokines and improvement in metabolic parameters and locomotor activity, followed by minor alterations compatible with apoptosis and astrogliosis in the hippocampus and prefrontal cortex. These results suggest that the anti-inflammatory effect of simvastatin plays a crucial role in restoring energy production, maintaining a hypermetabolic state necessary for the recovery and survival of these CLP-rats.

HSP-Target of Therapeutic Agents in Sepsis Treatment.

Sepsis is a syndrome characterized by a dysregulated inflammatory response, cellular stress, and organ injury. Sepsis is the main cause of death in intensive care units worldwide, creating need for research and new therapeutic strategies. Heat shock protein (HSP) analyses have recently been developed in the context of sepsis. HSPs have a cytoprotection role in stress conditions, signal to immune cells, and activate the inflammatory response. Hence, HSP analyses have become an important focus in sepsis research, including the investigation of HSPs targeted by therapeutic agents used in sepsis treatment. Many therapeutic agents have been tested, and their HSP modulation showed promising results. Nonetheless, the heterogeneity in experimental designs and the diversity in therapeutic agents used make it difficult to understand their efficacy in sepsis treatment. Therefore, future investigations should include the analysis of parameters related to the early and late immune response in sepsis, HSP localization (intra or extracellular), and time to the onset of treatment after sepsis. They also should consider the differences in experimental sepsis models. In this review, we present the main results of studies on therapeutic agents in targeting HSPs in sepsis treatment. We also discuss limitations and possibilities for future investigations regarding HSP modulators.

Inhibition of neuronal nitric oxide synthase activity does not alter vasopressin secretion in septic rats.

BACKGROUND/PURPOSE: During the early phase of sepsis, hypotension is accompanied by increase of plasma vasopressin hormone (AVP) levels, which decline during the late phase. This hypotension is due in part to increase of nitric oxide (NO) synthesis by nitric oxide synthase (NOS) enzyme. Neuronal isoform of this enzyme (nNOS) is present in vasopressinergics neurons of hypothalamus, but its role in vasopressin secretion during sepsis is unknown. METHODS: We evaluated the role of nNOS in NO production and vasopressin secretion during sepsis. Wistar rats received 7-nitroindazole (50 mg/kg, i.p.), an inhibitor of nNOS activity, or vehicle and were submitted to septic stimulus by cecal ligation and puncture (CLP). At the time points 0, 4, 6, 18 and 24 h after sepsis induction the animals were decapitated and neurohypophysis and hypothalamus were removed for analysis of vasopressin content and NOS activity, respectively. Hematocrit, serum sodium, osmolality, proteins and plasmatic AVP were quantified. RESULTS: Mortality was not affected by 7-nitroindazole (7-NI). Sodium and plasma proteins levels decreased after CLP and the treatment anticipated the protein loss, and delayed serum sodium decrease. Septic animals treated with 7-NI showed decrease of osmolality 4 h after CLP. Nitric oxide synthase activity in hypothalamus increased at 4 and 24 h after CLP and was reduced with 7-NI. Neurohypophysis content of AVP diminished after CLP and 7-NI did not alter this parameter. Plasma AVP levels increased at 6 h and decreased 18 and 24 h after CLP. Treatment with 7-NI did not alter plasma vasopressin levels. CONCLUSION: We concluded that nNOS does not have a substantial role in vasopressin secretion during experimental sepsis.

Impairment of osmotic challenge-induced neurohypophyseal hormones secretion in sepsis survivor rats.

BACKGROUND/PURPOSE: Recent studies have reported that sepsis survivors show impaired central nervous system functions. The osmoregulation in this post-sepsis condition has not been well investigated. In the present study, we evaluated the secretion of neurohypophyseal hormones, arginine vasopressin (AVP) and oxytocin (OT), and water intake induced by osmotic challenge in survivor rats. METHODS: Wistar rats were submitted to sepsis by cecal ligation and puncture (CLP). Five days after CLP surgery, the survivor and naive animals were stimulated with an osmotic challenge consisting of hypertonic saline administration. Thirty minutes later, blood and brain were collected for determination of osmolality, nitrite, interleukin (IL)-1ß, IL-6, AVP and OT levels and c-fos expression analysis of hypothalamic supraoptic nuclei (SON), respectively. In another set of sepsis survivor animals, water intake was measured for 240 min after the osmotic stimulus. RESULTS: High levels of nitrite and IL-1ß, but not IL-6, were found in the plasma of sepsis survivors and this long-term systemic inflammation was not altered by the osmotic challenge. Moreover, the AVP and OT secretion (but not the osmolality) and c-fos expression in SON were significantly attenuated in CLP survivor animals. Additionally, there was no alteration in the water intake response induced by osmotic challenge in the sepsis survivor group. CONCLUSION: The results suggest that the inflammatory components mediated a persistent impairment in the component of the osmoregulatory reflex affecting the secretion of neurohypophyseal hormones in sepsis survivor animals.

Environmental enrichment reduces brain damage in hydrocephalic immature rats.

PURPOSE: We investigate the effects of environmental enrichment (EE) on morphological alterations in different brain structures of pup rats submitted to hydrocephalus condition. METHODS: Hydrocephalus was induced in 7-day-old pup rats by injection of 20% kaolin into the cisterna magna. Ventricular dilatation and magnetization transfer to analyze myelin were assessed by magnetic resonance. Hydrocephalic and control rats exposed to EE (n = 10 per group) were housed in cages with a tunnel, ramp, and colored plastic balls that would emit sound when touched. The walls of the housing were decorated with colored adhesive tape. Moreover, tactile and auditory stimulation was performed daily throughout the experiment. Hydrocephalic and control rats not exposed to EE (n = 10 per group) were allocated singly in standard cages. All animals were weighed daily and exposed to open-field conditions every 2 days until the end of the experiment when they were sacrificed and the brains removed for histology and immunohistochemistry. Solochrome cyanine staining was performed to assess the thickness of the corpus callosum. The glial fibrillary acidic protein method was used to evaluate reactive astrocytes, and the Ki67 method to assess cellular proliferation in the subventricular zone. RESULTS: The hydrocephalic animals exposed to EE showed better performance in Open Field tests (p < 0.05), while presenting lower weight gain. In addition, these animals showed better myelination as revealed by magnetization transfer (p < 0.05). Finally, the EE group showed a reduction in reactive astrocytes by means of glial fibrillary acidic protein immunostaining and preservation of the proliferation potential of progenitor cells. CONCLUSION: The results suggest that EE can protect the developing brain against damaging effects caused by hydrocephalus.

Curcumin suppresses inflammatory cytokines and heat shock protein 70 release and improves metabolic parameters during experimental sepsis.

CONTEXT: Curcumin has been reported to have anti-inflammatory, antioxidant and hypoglycaemic properties, besides reducing mortality in sepsis. OBJECTIVE: This study evaluates the biological activities of a curcumin dispersion formulated by spray-drying in experimental sepsis. MATERIALS AND METHODS: Male Wistar rats were subjected to sepsis by caecal ligation and puncture (CLP), controls were sham operated. The animals were treated with curcumin dispersion (100 mg/kg, p.o.) or water for 7 days prior to CLP and at 2 h after surgery. One group was used to analyze curcumin absorption through HPLC; another had the survival rate assessed during 48 h; and from a third group, blood was collected by decapitation to analyze metabolic and inflammatory parameters. RESULTS: The plasma curcumin levels reached 2.5 ng/mL at 4 h, dropped significantly (p < 0.001) at 6 h (1.2 ng/mL), and were undetectable at 24 h in both groups. Curcumin temporarily increased the survival rate of the septic rats by 20%. Moreover, it attenuated glycaemia (p < 0.05) and volemia (p < 0.05) alterations typically observed during sepsis, and decreased the levels of the proinflammatory cytokines IL-1ß and IL-6 in plasma (p < 0.001) and peritoneal lavage fluid (p < 0.05) of septic rats. Serum HSP70 levels were decreased (p < 0.01) at 24 h after CLP. DISCUSSION AND CONCLUSION: Our results show that the curcumin dispersion dose employed was not detrimental to the septic rats. In fact, it temporarily increased their survival rate, improved important metabolic parameters, reduced proinflammatory cytokines and HSP70 production.

Brazilian actions to promote physiology learning and teaching in secondary and high schools.

Members of the Education Committee of the Brazilian Society of Physiology have developed multiple outreach models to improve the appreciation of science and physiology at the precollege level. The members of this committee act in concert with important Brazilian governmental strategies to promote training of undergraduate students in the teaching environment of secondary and high schools. One of these governmental strategies, the Programa Institucional de Bolsas de Iniciação à Docência, a Brazilian public policy of teaching enhancement implemented by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) since 2007, represents a well-articulated public policy that can promote the partnership between University and Schools (7). Furthermore, the Program "Novos Talentos" (New Talents)/CAPES/Ministry of Education is another government initiative to bring together university and high-level technical training with the reality of Brazilian schools. Linked to the New Talents Program, in partnership with the British Council/Newton Fund, CAPES recently promoted the visit of some university professors that coordinate New Talents projects to formal and informal educational science spaces in the United Kingdom (Science, Technology, Engineering, and Mathematics, Brazil-United Kingdom International Cooperation Program) to qualify the actions developed in this area in Brazil, and one of us had the opportunity to participate with this.

An alternative to the use of animals to teach diabetes mellitus.

We developed an alternative approach to teach diabetes mellitus in our practical classes, replacing laboratory animals. We used custom rats made of cloth, which have a ventral zipper that allows stuffing with glass marbles to reach different weights. Three mock rats per group were placed into metabolic cages with real food and water and with test tubes containing artificial urine, simulating a sample collection of 24 h. For each cage, we also provided other test tubes with artificial blood and urine, simulating different levels of hyperglycemia. The artificial "diabetic" urine contained different amounts of anhydrous glucose and acetone to simulate two different levels of glycosuria and ketonuria. The simulated urine of a nondiabetic rat was prepared without the addition of glucose or acetone. An Accu-Chek system is used to analyze glycemia, and glycosuria and ketonuria intensity were analyzed by means of a Urocolor bioassay. In the laboratory classroom, students were told that they would receive three rats to find out which one has type 1 or type 2 diabetes mellitus. To do so, they had to weigh the animals, quantify the water and food ingestion, and analyze the artificial blood and urine for glycemia, glycosuria, and ketonuria. Only at the end of class did we reveal that the urine and blood were artificial. Students were instructed to plot the data in a table, discuss the results within their group, and write an individual report. We have already used this practical class with 300 students, without a single student refusing to participate.

Oxytocin affects nitric oxide and cytokine production by sepsis-sensitized macrophages.

BACKGROUND/AIM: Oxytocin (OXT) secretion during cecal ligation puncture (CLP)-induced sepsis has not yet been examined. Although immune properties have been attributed to OXT, its effect on CLP-sensitized macrophages has never been investigated. We analyzed OXT secretion during CLP and its effect in CLP-sensitized macrophage cultures. METHODS: Male Wistar rats were decapitated 4, 6 or 24 h after CLP surgery or sham operation and blood, brain and neurohypophyses were collected for OXT measurements. In another set of animals we studied the effect of OXT on nitrite, tumor necrosis factor (TNF-α), interleukin (IL)-1ß and IL-10 production of peritoneal macrophages harvested at 6 and 24 h after CLP. RESULTS: In the early phase of sepsis (4-6 h), OXT levels increased in plasma and decreased in hypothalamus and neurohypophysis. In the late phase (24 h), plasma and neurohypophyseal levels remained basal. In the paraventricular, the OXT content remained low, but in the supraoptic increased. Macrophages of the early phase of sepsis pretreated with OXT and stimulated with lipopolysaccharide showed decreased nitrite, TNF-α and IL-1ß levels, but no alteration in IL-10 production. In the late phase, they showed reduction only on IL-1ß. CONCLUSIONS: OXT secretion during sepsis may represent a neuroendocrine response contributing to the overall host response to infection by decreasing the proinflammatory response and oxidative stress.

Microglial Activation Modulates Neuroendocrine Secretion During Experimental Sepsis.

Sepsis promotes an inflammatory state in the central nervous system (CNS) that may cause autonomic, cognitive, and endocrine changes. Microglia, a resident immune cell of the CNS, is activated in several brain regions during sepsis, suggesting its participation in the central alterations observed in this disease. In this study, we aimed to investigate the role of microglial activation in the neuroendocrine system functions during systemic inflammation. Wistar rats received an intracerebroventricular injection of the microglial activation inhibitor minocycline (100 µg/animal), shortly before sepsis induction by cecal ligation and puncture. At 6 and 24 h after surgery, hormonal parameters, central and peripheral inflammation, and markers of apoptosis and synaptic function in the hypothalamus were analyzed. The administration of minocycline decreased the production of inflammatory mediators and the expression of cell death markers, especially in the late phase of sepsis (24 h). With respect to the endocrine parameters, microglial inhibition caused a decrease in oxytocin and an increase in corticosterone and vasopressin plasma levels in the early phase of sepsis (6 h), while in the late phase, we observed decreased oxytocin and increased ACTH and corticosterone levels compared to septic animals that did not receive minocycline. Prolactin levels were not affected by minocycline administration. The results indicate that microglial activation differentially modulates the secretion of several hormones and that this process is associated with inflammatory mediators produced both centrally and peripherally.

Vasopressin and copeptin release during sepsis and septic shock.

Sepsis is defined as a potentially fatal organ dysfunction caused by a dysregulated host response to infection. Despite tremendous progress in the medical sciences, sepsis remains one of the leading causes of morbidity and mortality worldwide. The host response to sepsis and septic shock involves changes in the immune, autonomic, and neuroendocrine systems. Regarding neuroendocrine changes, studies show an increase in plasma vasopressin (AVP) concentrations followed by a decline, which may be correlated with septic shock. AVP is a peptide hormone derived from a larger precursor (preprohormone), along with two peptides, neurophysin II and copeptin. AVP is synthesized in the hypothalamus, stored and released from the neurohypophysis into the bloodstream by a wide range of stimuli. The measurement of AVP has limitations due to its plasma instability and short half-life. Copeptin is a more stable peptide than AVP, and its immunoassay is feasible. The blood concentrations of copeptin mirror those of AVP in many physiological states; paradoxically, during sepsis-related organ dysfunction, an uncoupling between copeptin and AVP blood levels appears to happen. In this review, we focus on clinical and experimental studies that analyzed AVP and copeptin blood concentrations over time in sepsis. The findings suggest that AVP and copeptin behave similarly in the early stages of sepsis; however, we did not find a proportional decrease in copeptin concentrations as seen with AVP during septic shock. Copeptin levels were higher in nonsurvivors than in survivors, suggesting that copeptin may work as a marker of severity or sepsis-related organ dysfunction.

Tooth movement activates the central amygdala and the lateral hypothalamus by the magnitude of the force applied.

OBJECTIVE: To determine if the magnitude of the force used to induce incisor tooth movement promotes distinct activation in cells in the central amygdala (CEA) and lateral hypothalamus (LH) of rats. Also, the effect of morphine on Fos immunoreactivity (Fos-IR) was investigated in these nuclei. MATERIALS AND METHODS: Adult male rats were anesthetized and divided into six groups: only anesthetized (control), without orthodontic appliance (OA), OA but without force, OA activated with 30g or 70g, OA with 70g in animals pretreated with morphine (2 mg/kg, intraperitoneal). Three hours after the onset of the experiment the rats were reanesthetized and perfused with 4% paraformaldehyde. The brains were removed and fixed, and sections containing CEA and LH were processed for Fos protein immunohistochemistry. RESULTS: The results show that in the control group, the intramuscular injection of a ketamine/ xylazine mixture did not induce Fos-IR cells in the CEA or in the LH. Again, the without force group showed a little Fos-IR. However, in the 70g group the Fos-IR was the biggest observed (P < .05, Tukey) in the CEA and LH compared with the other groups. In the 30g group, the Fos-IR did not differ from the control group, the without OA group, and the without force group. Furthermore, pretreatment with morphine in the 70g group reduced Fos-IR in these regions. CONCLUSIONS: Tooth movement promotes Fos-IR in the CEA and LH according to the magnitude of the force applied.

Sepsis-induced encephalopathy impairs descending nociceptive pathways in rats.

Sepsis-associated encephalopathy (SAE) is a significant problem in patients with sepsis, and it is associated with a decrease in cognitive and sensitivity capability induced by systemic inflammation. SAE is implicated in reversible brain damage of several regions related to cognition, emotion, and sensation; however, it is not well established if it could affect brain regions associated with nociceptive modulation. Here were evaluated the nociceptive thresholds in rats with systemic inflammation induced by cecal ligation puncture (CLP). After 24 h of CLP, it was observed an increase in nociceptive threshold in all tests. Periaqueductal gray, rostroventral medulla, critical regions for descending nociceptive modulation, were evaluated and showed enhanced pro-inflammatory cytokines as well as glial activation. These results suggest that systemic inflammation could compromise descending facilitatory pathways, impairing nociceptive sensory functioning.

Simvastatin Prevents Long-Term Cognitive Deficits in Sepsis Survivor Rats by Reducing Neuroinflammation and Neurodegeneration.

Sepsis-associated encephalopathy causes brain dysfunction that can result in cognitive impairments in sepsis survivor patients. In previous work, we showed that simvastatin attenuated oxidative stress in brain structures related to memory in septic rats. However, there is still a need to evaluate the long-term impact of simvastatin administration on brain neurodegenerative processes and cognitive damage in sepsis survivors. Here, we investigated the possible neuroprotective role of simvastatin in neuroinflammation, and neurodegeneration conditions of brain structures related to memory in rats at 10 days after sepsis survival. Male Wistar rats (250-300 g) were submitted to cecal ligation and puncture (CLP, n = 42) or remained as non-manipulated (naïve, n = 30). Both groups were treated (before and after the surgery) by gavage with simvastatin (20 mg/kg) or an equivalent volume of saline and observed for 10 days. Simvastatin-treated rats that survived to sepsis showed a reduction in the levels of nitrate, IL1-ß, and IL-6 and an increase in Bcl-2 protein expression in the prefrontal cortex and hippocampus, and synaptophysin only in the hippocampus. Immunofluorescence revealed a reduction of glial activation, neurodegeneration, apoptosis, and amyloid aggregates confirmed by quantification of GFAP, Iba-1, phospho Ser396-tau, total tau, cleaved caspase-3, and thioflavin-S in the prefrontal cortex and hippocampus. In addition, treated animals presented better performance in tasks involving habituation memory, discriminative, and aversive memory. These results suggest that statins exert a neuroprotective role by upregulation of the Bcl-2 and gliosis reduction, which may prevent the cognitive deficit observed in sepsis survivor animals.

Thermoregulation and vasopressin secretion during polymicrobial sepsis.

OBJECTIVE: We investigated the time course of thermoregulation, nitric oxide (NO) formation and hydroelectrolytic alterations, as well as mean arterial pressure and arginine vasopressin (AVP) secretion, in experimental sepsis induced by cecal ligation and puncture (CLP). METHODS: Male Wistar rats submitted to CLP or a sham operation were divided into 4 groups, as follows: group 1, for survival rate evaluation for 24 h; group 2, for body temperature (Tb) analysis; group 3, for mean arterial pressure registration, and group 4, for blood collection and processing of the neurohypophysis and hypothalamic nuclei 0, 2, 4, 6 and 24 h after surgery. AVP levels and content were measured in plasma, neurohypophysis and the hypothalamic paraventricular and supraoptic nuclei. RESULTS: Animals which underwent CLP showed high mortality, a progressive decrease in mean arterial pressure and an increase in plasma NO. Tb dropped during the first 4 h and showed a progressive increase 6 h after surgery. Plasma AVP levels increased immediately after CLP surgery and again at 6 h, before returning to basal levels at 24 h. This was followed by a depletion of neurohypophyseal AVP content at 4 h that continued until 24 h. AVP content in the supraoptic nucleus was elevated 24 h after CLP surgery, while in the paraventricular nucleus, an increase was observed at 6 h and 24 h. CONCLUSIONS: In the present study, laparotomy and hypotension may have been responsible for the increase in plasma AVP in the initial phase of polymicrobial sepsis, and this may have contributed to the observed hypothermia. Moreover, an apparently impaired replenishment of AVP content in the neurohypophysis, possibly due to increased NO formation, may explain the impaired AVP secretion in the late phase of severe sepsis.

Kaolin-induced hydrocephalus causes acetylcholinesterase activity dysfunction following hypothalamic damage in infant rats.

In hydrocephalus, the progressive accumulation of cerebrospinal fluid (CSF) causes dilatation of the lateral ventricles affecting the third ventricle and diencephalic structures such as the hypothalamus. These structures play a key role in the regulation of several neurovegetative functions by the production of the hormones. Since endocrine disturbances are commonly observed in hydrocephalic children, we investigated the impact of progressive ventricular dilation on the hypothalamus of infant rats submitted to kaolin-induced hydrocephalus. Seven-day-old infant rats were submitted to hydrocephalus induction by kaolin 20% injection method. After 14 days, the animals were decapitated and brain was collected to analyze mitochondrial function, neuronal activity by acetylcholinesterase (AChE) enzyme, oxidative damage, glial activation, and, neurotransmission-related proteins and anti-apoptotic processes in the hypothalamus. The hydrocephalic animals showed reduction in respiratory rates in the States of phosphorylation (P < 0.01) and non-phosphorylation (P < 0.05); increase in AChE activity in both the cytosol (P < 0.05) and the membrane (P < 0.01); decrease in synaptophysin (P < 0.05) and Bcl-2 (P < 0.05) contents and; increase in protein carbonyl (P < 0.01), GFAP (P < 0.01) and Iba-1 (P < 0.05) levels. The results demonstrate that ventricular dilation causes hypothalamic damage characterized by cholinergic dysfunction and suggests further investigation of the synthesis and secretion of hormones to generate new approaches and to assist in the treatment of hydrocephalic patients with hormonal alterations.

Neuroprotective action of Eicosapentaenoic (EPA) and Docosahexaenoic (DHA) acids on Paraquat intoxication in Drosophila melanogaster.

Several studies have shown the protective effects of dietary enrichment of omega-3 (ω-3) long-chain fatty acids in several animal models of neurodegenerative diseases. Here we investigate if eicosapentaenoic (EPA) and Docosahexaenoic (DHA) acids (ω-3) protect against neurodegeneration mediated by the exposure to a widely used herbicide Paraquat (PQ) (1,1'-dimethyl-4-4'-bipyridinium dichloride), focusing on mitochondrial metabolism using Drosophila melanogaster as a model. Dietary ingestion of PQ for 3 days resulted in the loss of citrate synthase content, respiratory capacity impairment and exacerbated H2O2 production per mitochondrial unit related to complex I dysfunction, and high lactate accumulation in fly heads. PQ intoxication lead to 1) the loss of ELAV (embryonic lethal abnormal vision) and α-spectrin, essential proteins of neuronal viability and synaptic stability; 2) increased gamma-secretase activity, an enzyme related to APP release; and 3) increased the amyloid fibrils contents. All these toxic effects induced by PQ were prevented by concomitant dietary ingestion of EPA/DHA, suggesting that a neuroprotective effect of ω-3 also involves mitochondrial protection. In conclusion, concomitant EPA and DHA ingestion protects against PQ-induced neuronal and mitochondrial dysfunctions frequently found in neurodegenerative processes reinforcing its protective role against environmental neurodegenerative diseases.

Autonomic dysfunction in experimental sepsis induced by cecal ligation and puncture.

A systemic inflammatory response to infection characterizes sepsis which associated to refractory hypotension, turns into severe sepsis. Our aim was to evaluate hormonal and cardiovascular alterations after experimental sepsis induced by cecal ligation and puncture (CLP). Male Wistar rats (200-250 g) were submitted to CLP or sham operation. The animals were decapitated at 0, 2, 4, 6 and 8 h after surgery for collection of blood samples for plasma osmolality, sodium and vasopressin (AVP) measurements. The mean arterial pressure (MAP) and heart rate (HR) were recorded 1 h before and to each 1 h during 5hs after surgery. The spontaneous baroreflex sensitivity and spectral analysis of HR and MAP variability were analyzed after recording. The plasma osmolality and sodium did not show any alterations compared to the sham group. MAP decreased from 3 h (85 vs.103 mm Hg, P<0.05) to 5 h in the CLP group (76 vs.106 mm Hg, P<0.05). This was accompanied by an increase in HR. The AVP plasma level was elevated at 4 h (6.0+/-1.1 vs. 1.1+/-0.2 pg/mL, P<0.05) and returned to basal levels at 8 h after CLP (2.3+/-0.5 vs. 1.9+/-0.2 pg/mL, P>0.05). A reduction in baroreflex sensitivity occurred 1 h after injury. The CLP group showed a reduction in overall variability, low-frequency power, and low/high-frequency ratio of HR and low-frequency power of MAP. The data suggest an impairment of autonomic control of the heart and vessels during polymicrobial sepsis. This reduction in autonomic nervous system activity causes the impairment of baroreflex that in turn may contribute to the reduction of vasopressin plasma levels in the late phase of severe sepsis.

Cytokines, cortisol, and nitric oxide as salivary biomarkers in oral lichen planus: a systematic review.

The etiopathogenesis of oral lichen planus (OLP) is still not fully elucidated, and it is believed that its development could involve a neuro-immune-endocrine profile. This systematic review investigated the relationship between cytokines, cortisol, and nitric oxide (NO) in the saliva of OLP patients. An electronic search was conducted in Pubmed/Medline, Scopus, LIVIVO, and Web of Science databases with no restriction of language to identify studies published up to December 2017. Data extraction was performed using the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A total of 140 articles were retrieved, and 32 articles fulfilled the inclusion criteria (cytokines = 17; cortisol = 9; NO = 6). The most studied cytokines in the saliva of OLP patients were interleukins IL-4, IL-6, IL-8, IFN-Ò¯, and TNF-α, which were higher in OLP patients than in healthy controls (HC). Salivary cortisol was found to be higher in OLP than in HC in most (55.5%) of the selected studies, and all studies related to NO found higher levels of this marker in OLP than in HC. Despite controversial results, our review suggests that OLP patients have an increased inflammatory response, as indicated by the proinflammatory profile of salivary cytokines. In addition, we conclude that salivary cytokine and NO measurements may have significant diagnostic and prognostic potential for monitoring disease activity and therapeutic responses in OLP.

Participation of iNOS-derived NO in hypothalamic activation and vasopressin release during polymicrobial sepsis.

Clinical and experimental studies with LPS injection have shown an increase in vasopressin (AVP) secretion in the early phase of severe sepsis, which is subsequently reduced despite persistent hypotension. The aim of this study was to evaluate the role of inducible nitric oxide synthase (iNOS)-derived NO in hypothalamic activation and in AVP release during severe sepsis induced by cecal ligation and puncture (CLP). Male Wistar rats received i.p. injections of aminoguanidine, an iNOS inhibitor, or saline 30 min before CLP or sham surgeries (controls). CLP led to increased plasma nitrate levels, protein leakage and hypotension and caused mortality of 80% by 24 h. Expression of c-fos in paraventricular (PVN), supraoptic (SON) and organum vasculosum of lamina terminalis (OVLT) nuclei, as well as plasma AVP concentration were increased at 6 h but reduced to basal levels 24 h after CLP. Aminoguanidine pre-treatment prevented the increase in plasma nitrate levels and hypotension in the first 6 h. It also reduced AVP secretion and hypothalamic c-fos expression. After 24 h, the pre-treatment reduced plasma nitrate levels, protein leakage and caused a partial recovery of c-fos expression in SON and OVLT but did not affect AVP release. Furthermore, mortality was reduced to 43%. We conclude that during the early phase of severe sepsis hypotension caused by the iNOS-derived NO is partially responsible for the hypothalamic activation and AVP release. In the late phase, however, the iNOS-derived NO prevents brain activation blunting AVP secretion contributing to hypotension, irreversible shock and animal death.