Effects of systemic nicotine, alcohol or their combination on cholinergic markers in the frontal cortex and hippocampus of rat.

Acute alcohol (Alc) intoxication has been shown to decrease choline acetyltransferase (ChAT) in the rat brain. The present study extends that finding by examining the effects of nicotine (Nic), Alc, and their combination on ChAT and acetylcholinesterase (AChE) in the frontal cortex and hippocampus of rat. The samples were collected at 30 and 120 min after intraperitoneal administration of saline (0.9%, control), Nic (1 mg/kg), Alc (1 g/kg), and Nic + Alc and analyzed by RT-PCR, Western blot and colorimetry. Alc alone considerably reduced ChAT mRNA expression, whereas Nic alone decreased AChE mRNA expression. In contrast, Nic + Alc exposure had resulted in no significant change in the parameters. These findings are consistent with the results of the Western blot and AChE activity analysis. The results, therefore, indicate that Nic and Alc alone may interact with the central cholinergic system. This interactive effect may contribute to a frequent association of tobacco and Alc consumption.