The blockade of kappa opioid receptors exacerbates alveolar bone resorption in rats.

Objectives: Bone resorption associated to chronic diseases, such as arthritis and periodontitis, results from exacerbated immuno-inflammatory host response that leads to tissue breakdown. The significance of opioid pathways as endogenous modulators of inflammatory events has already been described. Thus, the aim of this work is to determine whether some of the main three opioid receptors are endogenously activated to prevent bone loss during experimentally-induced alveolar bone resorption.

Koh group influence on titanium surfaces and pure sol-gel silica for enhanced osteogenic activity.

Although, the excellent level of success of titanium surfaces is based on the literature, there are some biological challenges such as unfavorable metabolic conditions or regions of poor bone quality where greater surface bioactivity is desired. Seeking better performance, we hypothesized that silica-based coating via sol-gel route with immersion in potassium hydroxide basic solution induces acceleration of bone mineralization. This in vitro experimental study coated titanium surfaces with bioactive glass synthesized by route sol-gel via hydrolysis and condensation of chemical alkoxide precursor, tetraethylorthosilicate (TEOS) and/or deposition of chemical compound potassium hydroxide (KOH) to accelerate bone apposition.

Antinociceptive response in transgenic mice expressing rat tonin.

Angiotensin II (Ang II) may be produced directly from angiotensinogen by tonin. Studies have demonstrated that Ang II and its metabolite Ang-(1-7) produce antinociception in pain animal models. The aim of the present study was to determine whether the transgenic mice that express rat tonin (TGM(rTon)) show altered nociceptive behavior and investigate the possible involvement of angiotensin metabolites.

δ-Opioid receptor agonist SNC80 induces central antinociception mediated by Ca2+ -activated Cl- channels.

Objectives: The aim of this study was to determine whether Ca(2+)-activated Cl(-) channels (CaCCs) are involved in central antinociception induced by the activation of µ-, δ- and κ-opioid receptors.

Methods: The nociceptive threshold for thermal stimulation was measured using the tail-flick test in Swiss mice. The drugs were administered via the intracerebroventricular route.

Peripheral antinociception induced by δ-opioid receptors activation, but not μ- or κ-, is mediated by Ca²⁺-activated Cl⁻ channels.

Studies have demonstrated that the L-arginine/NO/cGMP pathway and the potassium and calcium channels are involved in the mechanisms underlying opioid receptor activation. As additional pathways may participate in the observed antinociceptive effects following opioid exposure, the aim of our study was to determine whether Ca(2+)-activated Cl(-) channels (CaCCs) are involved in peripheral antinociception induced by μ-, δ- and κ-opioid receptor activation. Hyperalgesia was induced by intraplantar injection of prostaglandin E(2) (PGE(2), 2 μg).

Peripheral kappa opioid receptors activation reduces alveolar bone loss in rats by modulating interleukin-6 and -10.

Objective: The beneficial effects of kappa opioid agonist U-50,488 in preventing periodontal disease (PD) progression in rats have already been described, but its mechanism of action is unknown. The present study evaluated the expression of TNF-α, IL-6, IL-8 and IL-10 in the gingival tissues of rats with ligature-induced PD, treated with U-50,488. It also correlated the effects of this agonist with myeloperoxidase (MPO) activity and the presence of osteoclasts.

(99m)Tc-labeled-1-thio-beta-d-glucose as a new tool to temporomandibular joint inflammatory disorders diagnosis.

Aim: The aim of this study was to evaluate early detection of temporomandibular joint (TMJ) inflammatory changes based on 1-thio-beta-d-glucose radiolabeled with technetium-99m.

Method: The method applied a TMJ inflammation model in rats followed by radiopharmaceutical synthesis, intravenous administration of (99m)Tc-1-TG and kinetic scintigraphy imaging.

Results: Results show a significant difference of (99m)Tc-1-TG uptake between inflamed TMJ and the control joint.

Myeloperoxidase content is a marker of systemic inflammation in a chronic condition: the example given by the periodontal disease in rats.

The study aimed to evaluate the suitability of myeloperoxidase (MPO) content as a local indicator of chronic inflammation, using the periodontal disease model. Anesthetized adult male Holtzman rats had their second left maxilar molar tied by a thread for 11 days and were then killed. Blood samples and photographic images from histopathological inflamed and noninflamed (contralateral) neighboring gingivomucosal specimens were collected for cell counts and MPO level analysis.

Central antinociception induced by mu-opioid receptor agonist morphine, but not delta- or kappa-, is mediated by cannabinoid CB1 receptor.

Background And Purpose: It has been demonstrated that cannabinoids evoke the release of endogenous opioids to produce antinociception; however, no information exists regarding the participation of cannabinoids in the antinociceptive mechanisms of opioids. The aim of the present study was to determine whether endocannabinoids are involved in central antinociception induced by activation of mu-, delta- and kappa-opioid receptors.

Experimental Approach: Nociceptive threshold to thermal stimulation was measured according to the tail-flick test in Swiss mice.