Answer
Li reduces brain inositol levels.Phosphoinositede -based signalling bringsto the cell an incredibly richmodulation potentiality, keeping in mind thepresence of six hydroxyl groupson the inositol ring which can be found in a phosphorilated state. The firstround of phosphoinositide-derived second messengers arrived with inositol 1,4,5 trisphosphate (Ins(1,4,5)P3) and DAG. They derive from PLChydrolysis and PtIns (4,5)P2,a minor lipid constituent of cell membranes. The former releases Ca2+from intracellular stores, while the later activatescertain PKC isoforms. Ins(1,4,5)P3can be further phosphorylated to inositol(1,3,4,5) tetrakisphosphate, a molecule that may also have secondmessenger functions. It can in turn be a substrate for phosphatases andkinases and yield inositol (3,4,5,6)tetrakisphosphate, whose functions onthe inhibition of the ionic conductance through Ca2+- activated chloridechannels is well reported. It seems likely that a family ofphosphoinositolsdownstream of Ins(1,4,5)P3could be used by cells to modulate specificfunctions. A lithium inhibition of purified inositol polyphosphate 1-phosphatase, which metabolizes Ins(1,4)P2, Ins(1,3)P2, and Ins(1,3,4)P3.Lithium inhibits IMPs in vitro with a Ki(0.8mM), which is within thetherapeutic range (0.5-1.5mM) for lithium treatment of patients with bipolar disorder.
Work Step by Step
Li reduces brain inositol levels.Phosphoinositede -based signalling bringsto the cell an incredibly richmodulation potentiality, keeping in mind thepresence of six hydroxyl groupson the inositol ring which can be found in a phosphorilated state. The firstround of phosphoinositide-derived second messengers arrived with inositol 1,4,5 trisphosphate (Ins(1,4,5)P3) and DAG. They derive from PLChydrolysis and PtIns (4,5)P2,a minor lipid constituent of cell membranes. The former releases Ca2+from intracellular stores, while the later activatescertain PKC isoforms. Ins(1,4,5)P3can be further phosphorylated to inositol(1,3,4,5) tetrakisphosphate, a molecule that may also have secondmessenger functions. It can in turn be a substrate for phosphatases andkinases and yield inositol (3,4,5,6)tetrakisphosphate, whose functions onthe inhibition of the ionic conductance through Ca2+- activated chloridechannels is well reported. It seems likely that a family ofphosphoinositolsdownstream of Ins(1,4,5)P3could be used by cells to modulate specificfunctions. A lithium inhibition of purified inositol polyphosphate 1-phosphatase, which metabolizes Ins(1,4)P2, Ins(1,3)P2, and Ins(1,3,4)P3.Lithium inhibits IMPs in vitro with a Ki(0.8mM), which is within thetherapeutic range (0.5-1.5mM) for lithium treatment of patients with bipolar disorder.
