▁my o - inos it ol ▁from ▁gl uc ose ▁ 6 - ph osph ate . ▁In ▁the ▁first ▁step , ▁gl uc ose ▁ 6 - ph osph ate ▁is ▁converted ▁to ▁D - inos it ol ▁ 1 ▁mon oph osph ate ▁by ▁the ▁en zym e ▁gl uc ose ▁ 6 ▁ph osph ate ▁cycl ase . ▁In os it ol ▁mon oph osph at ase ▁catal y zes ▁the ▁final ▁step ▁in ▁which ▁D - inos it ol ▁ 1 ▁mon oph osph ate ▁is ▁de ph osph ory l ated ▁to ▁form ▁my o - inos it ol . ▁ ▁C lin ical ▁significance ▁▁ ▁In os it ol ▁mon oph osph at ase ▁has ▁histor ically ▁been ▁believed ▁to ▁be ▁a ▁direct ▁target ▁of ▁l ith ium , ▁the ▁primary ▁treatment ▁for ▁b ip olar ▁dis order . ▁It ▁is ▁thought ▁that ▁l ith ium ▁acts ▁according ▁to ▁the ▁in os it ol ▁de ple tion ▁hypothesis : ▁l ith ium ▁produces ▁its ▁th era pe ut ic ▁effect ▁by ▁in hib iting ▁I MP ase ▁and ▁therefore ▁decre asing ▁levels ▁of ▁my o - inos it ol . ▁Scient ific ▁support ▁for ▁this ▁hypothesis ▁exists ▁but ▁is ▁limited ; ▁the ▁complete ▁role ▁of ▁l ith ium ▁and ▁in os it ol ▁mon oph osph at ase ▁in ▁tre ating ▁b ip olar ▁dis order ▁or ▁reducing ▁my o - inos it ol ▁levels ▁is ▁not ▁well ▁understood . ▁ ▁In ▁support ▁of ▁the ▁in os