Nitric oxide and anglotensin II receptors mediate the pressor effect of angiotensin II: A study in conscious and zoletil-anesthetized rats

The circumventricular structures of the central nervous system and nitric oxide are involved in arterial blood pressure control, and general anesthesia may stimulate the central renin-angiotensin system. We therefore investigated the central role of angiotensin 11 and nitric oxide on the regulation of systemic arterial blood pressure in conscious and anesthetized rats. METHODS: Rats with stainless steel cannulae implanted into their lateral ventricle were studied. We injected the AT(1) and AT(2) angiotensin 11 receptor antagonists, losartan and PD123319, L-NAME, 7-nitroindazole (nitric oxide synthetase inhibitors), and FK409 (nitric oxide donor agent) into the lateral ventricles. Mean arterial blood pressure (MAP) was recorded in conscious and zoletil-anesthetized rats. RESULTS: Mean +/- (SEM) baseline MAP was 117.5 +/- 2 mm Hg. Angiotensin II injected into the brain lateral ventricle increased MAP from 136.5 +/- 2 min Hg to 138.5 +/- 4 mm Hg (Delta 16 +/- 3 mm Hg to Delta 21 +/- 3 mm Hg) for all experimental groups versus control from 116 +/- 2 mm Hg to 120 +/- 3 mm Hg (Delta 3 +/- 1 mm Hg to A5 +/- 2 mm Hg) (P < 0.05). L-NAME or 7-nitroindazole enhanced the angiotensin II pressor effect (P < 0.05). Prior injection of losartan and PD123319 decreased the angiotensin 11 pressor effect and the enhancement effect of L-NAME and 7-nitroindazole (P < 0.05). Zoletil anesthesia did not interfere with the effects of angiotensin 11, AT,, AT2 antagonists, or nitric oxide synthetase inhibitors. CONCLUSIONS: Endogenous nitric oxide functions tonically as a central inhibitory modulator of the angiotensinergic system. AT, and AT2 receptors influence the angiotensin 11 central control of arterial blood pressure. Zoletil anesthesia did not interfere with these effects. (Anesth Analg 2007;105:1293-7)

The impact of endogenous annexin A1 on glucocorticoid control of in ammatory arthritis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Similar anxiolytic-like effects following intra-amygdala infusions of benzodiazepine receptor agonist and antagonist: Evidence for the release of an endogenous benzodiazepine inverse agonist in mice exposed to elevated plus-maze test

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Endogenous corticosteroids and insulin in acute inflammation

Carrageenin-induced inflammatory responses in the hindpaws of rats were quantitated by measuring: (1) alterations in volumes of the paws; and (2) alterations in concentration of dye, previously injected intravenously, which was recovered in perfusates from the paws. The inflammatory response in one paw was attenuated by previously inducing an inflammatory response in the contralateral paw. The effect was abolished by pretreatment with insulin. Indexes of adrenal activity were increased after the induction of the inflammatory response and they were not attenuated by pretreatment with insulin. Adrenal hyperactivity was characterized by increased serum corticosterone concentration, decreased adrenal ascorbic acid content, and reduced number of circulating eosinophils. It is concluded that inflammatory stimuli which lead to alterations in microvessels depend on a facilitatory effect of insulin. This effect is antagonized by glucocorticoids released in enhanced concentrations after the application of noxious stimuli. Therefore, endogenous insulin and glucocorticoids act as modulators of inflammatory responses.

IL-12 and neutralization of endogenous IL-10 revert the in vitro antigen-specific cellular immunosuppression of paracoccidioidomycosis patients

Treatment of patients with paracoccidioidomycosis is still a challenge. Patients present defective lymphoproliferation and IFN-γ responses to the main Paracoccidioides brasiliensis antigen (gp43), which correlates with disease severity. Here, we demonstrated that the patients show also a defective synthesis of interleukin (IL)-12. Therefore, we attempted to revert this immune disfunction by adding IL-12 and neutralizing anti-IL-10 antibody to gp-43-stimulated peripheral blood mononuclear cell cultures. Both treatments increased IFN-γ secretion to levels observed with healthy sensitized individuals, but affected proliferation only modestly. When combined, the treatments further increased IFN-γ synthesis and cell proliferation. The addition of suboptimal concentrations of IL-2 also further increased the IL-12-mediated secretion of IFN-γ. Interestingly, the immune modulation was mostly antigen-specific, since the responses to Candida albicans' antigen were not affected. These results suggest that appropriate immune intervention with cytokines and/or anti-cytokines may help in the treatment of PCM. © 2002 Elsevier Science Ltd. All rights reserved.

Effect of storage of cuttings on the rooting of different cultivars of cut chrysanthemums (Dendranthema grandiflora Tzvelev) for two different seasons

Chrysanthemums are commercially propagated through cuttings. Pre-rooting storage of cuttings in the dark is a common practice among growers and companies that work and trade with chrysanthemum cuttings. Therefore, the maximum storage period for cuttings and differences in tolerance among cultivars has been investigated. Adventitious roots of cuttings can originate in almost any tissue, including the epidermis, stem cortex and pericycle, ray parenchyma, immature xylem and phloem cells, and pith. The aims of this work were to determine the effect of time of cold storage of cuttings (0, 1, 2, 3, 4, 5 and 6 weeks) on the rooting of four cut chrysanthemum cultivars (Super White, Sheena, Dark Orange Reagan and Town Talk) for two seasons of the year (summer and winter), and also to determine the origin of root formation in chrysanthemum cuttings. The study was carried out as a randomized complete block design with 5 replications for each storage treatment. Each plot was comprised of three cuttings that were examined 14 days after the cutting procedure. During the winter, the roots were studied by scanning electron microscopy (SEM) at the Electron Microscope Laboratory. The following conclusions were made: in winter, cold storage affected the rooting of cuttings, mainly after two weeks of storage for all cultivars. The rooting percentage was lower in the winter and the cuttings could be preserved for a shorter period. The source and growth of roots in chrysanthemum cuttings was found to be endogenous. After three days, callus formed in the pericycle and the first emergence of adventitious roots occurred by the fourth day of rooting. During the summer, cold storage could be up to 4 weeks without any problems.

Effect of phosphoric acid on the degradation of human dentin matrix

This study determined if dentin proteases are denatured by phosphoric acid (PA) used in etch-and-rinse dentin adhesives. Dentin beams were completely demineralized with EDTA for 30 days. We acid-etched experimental groups by exposing the demineralized dentin beams to 1, 10, or 37 mass% PA for 15 sec or 15 min. Control beams were not exposed to PA but were incubated in simulated body fluid for 3 days to assay their total endogenous telopeptidase activity, by their ability to solubilize C-terminal crosslinked telopeptides ICTP and CTX from insoluble dentin collagen. Control beams released 6.1 ± 0.8 ng ICTP and 0.6 ± 0.1 ng CTX/mg dry-wt/3 days. Positive control beams pre-incubated in p-aminophenylmercuric acetate, a compound known to activate proMMPs, released about the same amount of ICTP peptides, but released significantly less CTX. Beams immersed in 1, 10, or 37 mass% PA for 15 sec or 15 min released amounts of ICTP and CTX similar to that released by the controls (p > 0.05). Beams incubated in galardin, an MMP inhibitor, or E-64, a cathepsin inhibitor, blocked most of the release of ICTP and CTX, respectively. It is concluded that PA does not denature endogenous MMP and cathepsin activities of dentin matrices. © 2013 International & American Associations for Dental Research.

Effect of the bone marrow cell transplantation on elevated plus-maze performance in hippocampal-injured mice

Several reports have shown that the hippocampus plays an important role in different aspects of the emotional control. There is evidence that lesions in this structure cause behavioral disinhibition, with reduction of reactions expressing fear and anxiety. Thus, to portray the aptitude of cell therapy to abrogate injuries of hippocampal tissue, we examined the behavioral effects of bone marrow mononuclear cells (BMMCs) transplantation on C57BL/6 mice that had the hippocampus damaged by electrolytic lesion. For this purpose, mice received, seven days after bilateral electrolytic lesion in the dorsal hippocampus, culture medium or BMMCs expressing the enhanced green fluorescent protein (EGFP) transgene. One week after transplantation, animals were tested in the elevated plus-maze (EPM). On the whole, three assessment sessions in the EPM were carried out, with seven days separating each trial. Thirty-five days after the induction of injury, mice were sacrificed and their brains removed for immunohistochemistry. The behavioral evaluation showed that the hippocampal lesion caused disinhibition, an effect which was slightly lessened, from the second EPM test, in transplanted subjects. On the other hand, immunohistochemical data revealed an insignificant presence of EGFP+ cells inside the brains of injured mice. In view of such scenario, we hypothesized that the subtle rehabilitation of the altered behavior might be a result from a paracrine effect from the transplanted cells. This might have been caused by the release of bioactive factors capable of boosting endogenous recuperative mechanisms for a partial regaining of the hippocampal functions. © 2013 Elsevier B.V.

The hypotensive effect of the ruthenium complex [Ru(terpy)(bdq)NO](3+) is higher in male than in female spontaneously hypertensive rats (SHR)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Beneficial effect of annexin A1 in a model of experimental allergic conjunctivitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Endogenous opioid peptide-mediated neurotransmission in central and pericentral nuclei of the inferior colliculus recruits mu(1)-opioid receptor to modulate post-ictal antinociception

Background: The aim of the present work was to investigate the involvement of the mu(1)-endogenous opioid peptide receptor-mediated system in post-ictal antinociception. Methods: Antinociceptive responses were determined by the tail-flick test after pre-treatment with the selective mu(1)-opioid receptor antagonist naloxonazine, peripherally or centrally administered at different doses. Results: Peripheral subchronic (24 h) pre-treatment with naloxonazine antagonised the antinociception elicited by tonic-clonic seizures. Acute (10 min) pre-treatment, however, did not have the same effect. In addition, microinjections of naloxonazine into the central, dorsal cortical and external cortical nuclei of the inferior colliculus antagonised tonic-clonic seizure-induced antinociception. Neither acute (10-min) peripheral pre-treatment with naloxonazine nor subchronic intramesencephalic blockade of mu(1)-opioid receptors resulted in consistent statistically significant differences in the severity of tonic-clonic seizures shown by Racine's index (1972), although the intracollicular specific antagonism of mu(1)-opioid receptor decreased the duration of seizures. Conclusion: mu(1)-Opioid receptors and the inferior colliculus have been implicated in several endogenous opioid peptide-mediated responses such as antinociception and convulsion. The present findings suggest the involvement of mu(1)-opiate receptors of central and pericentral nuclei of the inferior colliculus in the modulation of tonic-clonic seizures and in the organisation of post-ictal antinociception. (C) 2011 Elsevier Ltd. All rights reserved.

Effect of sulfide concentration on autotrophic denitrification from nitrate and nitrite in vertical fixed-bed reactors

Autotrophic denitrification coupled with sulfide oxidation represents an interesting alternative for the simultaneous removal of nitrate/nitrite and sulfide from wastewaters. The applicability of such bioprocess is especially advantageous for the post treatment of effluents from anaerobic reactors, since they usually produce sulfides, which can be used as endogenous electron donor for autotrophic denitrification. This study evaluated the effect of sulfide concentration on this bioprocess using nitrate and nitrite as electron acceptors in vertical fixed-bed reactors. The results showed that intermediary sulfur compounds were mainly produced when excess of electron donor was applied, which was more evident when nitrate was used. Visual evidences suggested that elemental sulfur was the intermediary compound produced. There was also evidence that the elemental sulfur previously formed was being used when sulfide was applied in stoichiometric concentration relative to nitrate/nitrite. Nitrite was more readily consumed than nitrate. For both electron acceptors and sulfide concentrations tested, autotrophic denitrification was not affected by residual heterotrophic denitrification via endogenic activity, occurring as a minor additional nitrogen removal process. (C) 2012 Elsevier Ltd. All rights reserved.

Serotonin-2C receptors in the basolateral nucleus of the amygdala mediate the anxiogenic effect of acute imipramine and fluoxetine administration

A growing body of evidence indicates that facilitation of serotonin-2C receptor (5-HT2CR)-mediated neurotransmission in the basolateral nucleus of the amygdala (BLA) is involved in anxiety generation. We investigated here whether BLA 5-HT(2C)Rs exert a differential role in the regulation of defensive behaviours related to generalized anxiety (inhibitory avoidance) and panic (escape) disorders. We also evaluated whether activation of BLA 5-HT(2C)Rs accounts for the anxiogenic effect caused by acute systemic administration of the antidepressants imipramine and fluoxetine. Male Wistar rats were tested in the elevated T-maze after intra-BLA injection of the endogenous agonist 5-HT, the 5-HT2CR agonist MK-212 or the 5-HT2CR antagonist SB-242084. This test allows the measurement of inhibitory avoidance acquisition and escape expression. We also investigated whether intra-BLA administration of SB-242084 interferes with the acute anxiogenic effect caused by imipramine and fluoxetine in the Vogel conflict test, and imipramine in the elevated T-maze. While intra-BLA administration of 5-HT and MK-212 facilitated inhibitory avoidance acquisition, suggesting an anxiogenic effect, SB-242084 had the opposite effect. None of these drugs affected escape performance. Intra-BLA injection of a sub-effective dose of SB-242084 fully blocked the anxiogenic effect caused either by the local microinjection of 5-HT or the systemic administration of imipramine and fluoxetine. Our findings indicate that 5-HT(2C)Rs in BLA are selectively involved in the regulation of defensive behaviours associated with generalized anxiety, but not panic. The results also provide the first direct evidence that activation of BLA 5-HT(2C)Rs accounts for the short-term aversive effect of antidepressants.

Cholesterol-lowering effect of whole lupin (Lupinus albus) seed and its protein isolate

This study describes the hypocholesterolaemic effect of whole lupin and its protein in hamsters. The diets were: casein (control group HC), lupin protein isolate (group HPI) and whole lupin seed (group HWS). Diets from HPI and HWS promoted a significant reduction of total cholesterol and non-HDL cholesterol in the hamsters' plasma as compared with HC. The true digestibility of HPI and HC groups were similar and differed significantly from the HWS one, which in turn showed a significant difference in total sterol excretion as compared to the former groups. Histological analysis of the liver revealed that animals fed on HPI and HWS diets presented a low level of steatosis (level 1) as compared to the ones fed on HC diet (level 4). Our findings demonstrate that protein isolate from Lupinus albus from Brazil has a metabolic effect on endogenous cholesterol metabolism and a protector effect on development of hepatic steatosis. (C) 2011 Elsevier Ltd. All rights reserved.

Disruption of endogenous tidal rhythms of larval release linked to food supply and heat stress in an intertidal barnacle

The timing of larval release may greatly affect the survivorship and distribution of pelagic stages and reveal important aspects of life history tactics in marine invertebrates. Endogenous rhythms of breeding individuals and populations are valuable indicators of selected strategies because they are free of the neutral effect of stochastic environmental variation. The high-shore intertidal barnacle Chthamalus bisinuatus exhibits endogenous tidal and tidal amplitude rhythms in a way that larval release would more likely occur during fortnightly neap periods at high tide. Such timing would minimize larval loss due to stranding and promote larval retention close to shore. This fully explains temporal patterns in populations facing the open sea and inhabiting eutrophic areas. However, rhythmic activity breaks down to an irregular pattern in a population within the São Sebastião Channel subjected to large variation of food supply around a mesotrophic average. Peaks of chl a concentration precede release events by 6 d, suggesting resource limitation for egg production within the channel. Also, extreme daily temperatures imposing mortality risk correlate to release rate just 1 d ahead, suggesting a terminal reproductive strategy. Oceanographic conditions apparently dictate whether barnacles follow a rhythmic trend of larval release supported by endogenous timing or, alternatively, respond to the stochastic variation of key environmental factors, resulting in an erratic temporal pattern.