Modulation of phosphatidylinositol turnover on central nicotinic receptors.
AIM
To study the modulatory effects of phosphatidylinositol (PI) turnover on nicotinic receptors in CNS, and to study the relationship between brain nicotinic receptors and PI turnover.


METHODS
Effects of inositol phosphatase inhibitor lithium chloride (LiCl) and muscarinic receptor agonist oxotremorine (Oxo) on nicotine-induced convulsions were investigated in mice.


RESULTS
The effects of nicotine for producing convulsions were modified by LiCl 2.5-10 mmol.kg-1, revealing the convulsive effects of nicotine > 0.8 mg.kg-1 were increased by acute pretreatment with LiCl rather than oxotremorine. Mice were given LiCl 5.0 mmol.kg-1 once a day for 7 d, the ED50 value of nicotine for producing convulsions was increased from 0.58 to 0.97 mg.kg-1, suggesting that the sensitivity of central nicotinic receptors for mediating convulsions was decreased by chronic treatment with LiCl.


CONCLUSION
The functions of central nicotinic receptors were modulated by PI turnover.