[Experimental study of the effectiveness of local anesthetic activity of a new dimethylphenylacetamide-containing pharmaceutical composition in chronic periodontitis]. / Eksperimental'noe issledovanie po otsenke effektivnosti mestnoanesteziruyushchei aktivnosti novoi dimetilfenilatsetamid-soderzhashchei farmatsevticheskoi kompozitsii pri khronicheskom periodontite.

Novel anaesthetic formulation LHT-15-32 was studied. The experimental study involved 66 white mice, 15 Rana radibunda frogs and 50 male Sprague Dawley rats. Its acute intravenous and subcutaneous toxicity was determined in mice. Pain sensitivity threshold of upper second molar was determined in rats with experimental periodontitis. Oxidative stress activity and total antioxidant capacity were determined in rats' gingival mucosa by induced chemiluminescence. Tissue IL-1ß, IL-10 and TNF-a concentration was quantitatively assessed by ELISA. LHT-15-32 Na-blocking activity was studied on isolated neurons of Limnea stagnalis para-pharyngeal ganglion. Rana radibunda isolated sciatic nerve was perfused with LHT-15-32 to assess its conductivity. LHT-15-32 acute intravenous and subcutaneous toxicity was lower then that of its active substance LHT-4-00. The formulation infraorbital administration induced deep dental anaesthesia lasted longer than 70 min, activated local antioxidant defence system and decreased IL-1ß level in gingival tissue. At 10-6 to 10-3 M LHT-15-32 inhibited sciatic nerve conductivity and blocked Na+-channels of isolated neurons in dose-dependent manner. LHT-15-32 proved to be less toxic than active substance and lidocaine. The agent provides deep and prolonged anesthesia of the upper molar of rats in chronic apical periodontitis, lowers tissue concentration of pain cascade cytokines and oxidative stress activity and suppresses the action potential amplitude of a sensory nerve due to Na-blocking activity.

Aminoethane Sulfonic Acid Magnesium Salt Inhibits Ca2+ Entry Through NMDA Receptor Ion Channel In Vitro.

The effect of a cerebroprotective agent magnesium bis-aminoethanesulfonate (laboratory code FS-LKhT-317) on intracellular calcium concentration was studied by the fluorescent imaging technique on neuroglial cell culture from Spraque-Dawley rat hippocampus. The substance produced a pronounced inhibitory effect and suppressed NMDA receptor activity in concentrations of ≥50 µM. The observed effects were reversible or partially reversible and were detected by a decrease in Ca2+ signal amplitude in neurons in response to NMDA applications in a Mg2+-free medium and by inhibition of Ca2+ pulses in magnesium-free medium (elimination of magnesium block).