Mechanism of action of sodium hypochlorite

The choice of an irrigating solution for use in infected root canals requires previous knowledge of the microorganisms responsible for the infectious process as well as the properties of different irrigating solutions. Complex internal anatomy, host defenses and microorganism virulence are important factors in the treatment of teeth with asymptomatic apical periodontitis. Irrigating solutions must have expressive antimicrobial action and tissue dissolution capacity. Sodium hypochlorite is the most used irrigating solution in endodontics, because its mechanism of action causes biosynthetic alterations in cellular metabolism and phospholipid destruction, formation of chloramines that interfere in cellular metabolism, oxidative action with irreversible enzymatic inactivation in bacteria, and lipid and fatty acid degradation. The aim of this work is to discuss the mechanism of action of sodium hypochlorite based on its antimicrobial and physico-chemical properties.

Histochemical and ultrastructural assessment of the effects of indomethacin on the lipid content od decidual cells

The importance of lipid droplets and theirphospholipid stores as prostaglandin precursors in decidual cells was examined by administering indomethacin (0.2 mg) intraperitoneally to female mice on the fifth day of pregnancy. Control mice received the same volume of sesame oil (vehicle), all mice were sacrificed on the seventh day of prgnancy. Embryo implantation sites were collected and fixed in 3 porcento HgCl2- formalin or 3 porcento CaCl2-formalin solutions. Frozen sections were processed for the histological detection of total lipids and choline-containing phospholipids. some embryo implantation sites were also fixed with glutaraldehyde and processed for embedding in epoxy resin. The decidual reaction was less prominent in the endometrium of indomethacin-treated mice, there were strong reactions for total lipids and choline-containing phospholipids in fully differentiated decidual cells, and these were greather in treated mice. Ultrastructural analysis showed a higher content of lipid droplets in decidual cells of indomethacin-treated mice. These findings suggest that indomethacin affects lipid metabolism in the decidual reaction. The high level of lipid storage in decidual cells strongly suggests that these phospholipids, may be precursor for prostaglandins, nd that the inhibition of prostaglandin bisynthesis may affect the progress of cell already commited to decidualizatin

Inhibitory effect of propranolol on lipid synthesis in gonadectomized male hamster flank organs

Background. This papaer describes the inhibitory effect produced by propanolol pre-treatment on lipid synthesis in flank organs from intact, gonadectomized, and isoproterenol-treated male hamsters. Furthermore, the effect induced by the same treatments on gland sebum composition is reported. Methods. Different groups of male hamsters were injected daily with propranolol, isoproterenol or propranolol plusisoproterenol. Treatment-effect was evaluated determining the in vitro incorporation of radioactive acetate into lipids in hamster flank organs from intact and castrated animals. Additionally, radiolabeled lipids were isolated and identified using TLC and autoradiography as methods. Results. demonstrate that castration significantly decreases lipid synthesis in male hamster flank organs. In addition, propanolol treatment inhibits such synthesis in glands from intact, gonadectomized, and isoproterenol-treated animals. However, isoproterenol treatment was ineffective when compared to intact or gonadectomized control vehicle-treated animals. Lipid classes isolated and identified lipids either in castrated or in drug-treated animals were phospholipids, cholesterol, monoglycerides, fatty acids, waxes and cholesterol esters. Conclusions. Results indicate an inhibitory effect induced on lipid synthesis by ß-adrenergic receptor antagonist; however, ß-adrenergic agonists drugs do not stimulate it. Data suggest a permissive role of adrenergic hormones on lipid synthesis in intact and in gonadectomized animals. Futhermore, castration decreased the synthesis, suggesting that a tight coupling between ß-adrenergic receptors and androgen receptors may be a prerequisite for lipogenesis in this tissue. Pre-treatment does not modify sebum composition in gonadectomized animal glands. These data support the evidence that activation of ß-adrenergic receptors could be an independent factor in the lipid composition regulation process