title: Depolarizing effects of glycyrrhizin-derivatives relating to the blend effects with paeoniflorin in mouse diaphragm muscle.
abstract: Glycyrrhizin (GLR) and its newly synthesized derivatives, deoxoglycyrrhetol dihemisuccinate (I), deoxoglycyrrhetol dihemiphthalate (II), and the related compounds, carbenoxolone and glycyrrhetinic acid hemiphthalate (III), were assayed with or without paeoniflorin (PF) in mice diaphragm muscles. GLR-derivatives per se blocked the nerve-stimulated twitch tensions with the following order of potencies: carbenoxolone = III greater than II = I greater than GLR. The potencies paralleled the extent of muscle depolarization except in the case of I. GLR and I only increased muscle conductance. The blocking effects by GLR-derivatives per se on twitch responses are, therefore, can be explained by depolarization of muscle membranes and not by membrane conductance change. When carbenoxolone, II or GLR were blended with PF, the potentiation of the blocking effects observed may be related to the muscle depolarization rather than by the increase in membrane conductance.
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001565:Benzoates; D001952:Bridged-Ring Compounds; D002229:Carbenoxolone / Q000494:pharmacology; D003964:Diaphragm / Q000187:drug effects; D005960:Glucosides / Q000494:pharmacology*; D006027:Glycosides / Q000494:pharmacology*; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D019695:Glycyrrhizic Acid; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D039821:Monoterpenes; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000187:drug effects*; D009467:Neuromuscular Depolarizing Agents
chemical_list: D000893:Anti-Inflammatory Agents; D001565:Benzoates; D001952:Bridged-Ring Compounds; D005960:Glucosides; D006027:Glycosides; D039821:Monoterpenes; D009467:Neuromuscular Depolarizing Agents; C015423:peoniflorin; D019695:Glycyrrhizic Acid; D002229:Carbenoxolone; D006034:Glycyrrhetinic Acid