Effects of lidocaine on changes in intracellular Ca^2+ concentration and tension of the smooth muscle induced by adrenaline in porcine lingual arteries
Department of Dental Anesthesiology, School of Dentistry, Iwate Medical University
Department of Dental Anesthesiology, School of Dentistry, Iwate Medical University
抄録(英)
The purpose of this study was to clarify the effects and mechanisms of lidocaine (1.0×10^-3M)on changes in contraction of the smooth muscle induced by voltage dependent Ca^2+ channel (VDCC) stimulator, KCl(90mM), and receptor activated Ca^2+ channel (RACC) agonist, adrenaline(2×10^-5M), in porcine lingual arteries. The isometric tension and intracellular Ca^2+ concentration ( [Ca^2+]i) by the fura-2 microfluorometric methods were measured simultaneously, and from them we tried to deduce the depressing mechanism of lidocaine (1.0× 10^-3M) on the contraction. The results were obtained as follows:(1) Lidocaine depressed the increase of contraction and [Ca^2+]i induced by KCl and adrenaline in a concentration-dependent manner. (2) Lidocaine depressed the increase of contraction and [Ca^2+]i induced by adrenaline in normal physiological salt solution after depletion of the intracellular Ca^2+-sensitive Ca^2+ store. (3) Lidocaine depressed the increase of contraction and [Ca^2+]i induced by adrenaline in Ca^2+-free physiological salt solution. (4) Lidocaine had no effect on Ca^2+ induced Ca^2+ release(CICR) by caffein. These results suggest the following conclusions as follows, 1. Lidocaine depresses influx of Ca^2+ through VDCC and RACC. 2. Lidocaine inhibits the increase of [Ca^2+]i through IP_3 processes. 3. Lidocaine has no effect on CICR.