title: Dexmedetomidine (12.5 μg/mL) improves tissue distribution, anesthetic action, and hemodynamic effects of lidocaine after palatal infiltration in rats.
abstract: Dexmedetomidine hydrochloride (DEX) is a α2-adrenergic receptor agonist that causes vasoconstriction by acting on α2B-adrenergic receptors in peripheral blood vessels. The authors aimed to determine the influence of DEX on tissue distribution, anesthetic action, and hemodynamic effects of lidocaine in rats. The investigators injected indigo carmine-containing (14)C-labeled lidocaine hydrochloride (2 %) without and with 3.1, 12.5, or 50 μg/mL DEX or 10 μg/mL epinephrine into the right palatal mucosa mesial to the maxillary first molar of specific pathogen-free male Wistar rats. Autoradiography and liquid scintillation counting were performed to evaluate (14)C-labeled lidocaine concentrations in the palatal mucosa, maxillary bone, maxillary nerve, and peripheral blood. Somatosensory-evoked potentials were measured to analyze anesthetic action, and blood pressure and pulse rate were measured to compare hemodynamic effects. DEX extended the tissue distribution of lidocaine in a concentration-dependent manner. Lidocaine with 12.5 μg/mL DEX had similar blood peak arrival time and peak-to-peak amplitude as lidocaine with 10 μg/mL epinephrine, but it reduced pulse rate. The results of this study suggest that 12.5 μg/mL DEX improves tissue distribution, anesthetic action, and hemodynamic effects of lidocaine in rats. Therefore, 12.5 μg/mL DEX may be a suitable alternative to epinephrine in lidocaine formulations, especially for patients with ischemic heart disease and hypertension.
authors.affiliation: Department of Dental Anesthesiology, The Nippon Dental University School of Life Dentistry at Tokyo, 1-9-20 Fujimi Chiyoda-ku, Tokyo, 102-8159, Japan. pal.look.711womiginiiii@gmail.com.
authors.forename: Takuma
authors.initials: T
authors.lastname: Akimoto
authors.affiliation: Section of Radioisotope Research, Center of Odontology, The Nippon Dental University School of Life Dentistry at Tokyo, 1-9-20 Fujimi Chiyoda-ku, Tokyo, 102-8159, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Hashimoto
authors.affiliation: Department of Dental Anesthesiology, The Nippon Dental University School of Life Dentistry at Tokyo, 1-9-20 Fujimi Chiyoda-ku, Tokyo, 102-8159, Japan.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Sunada
mesh_terms: D000766:Anesthesia, Dental / Q000379:methods*; D000772:Anesthesia, Local / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D020927:Dexmedetomidine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006439:Hemodynamics / Q000187:drug effects; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010159:Palate; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
chemical_list: D000779:Anesthetics, Local; D020927:Dexmedetomidine; D008012:Lidocaine
keywords: Dexmedetomidine; Epinephrine; Ischemic heart disease and hypertension; Lidocaine; Vasoconstriction