The effect of an acute nicotine infusion on the local cerebral glucose utilization of the awake rat.

The effect of acute infusion of nicotine on local cerebral glucose utilization (LCGU) was studied in discrete regions of the central nervous system of the rat by means of the quantitative autoradiographic 2-deoxy-D-[1-14C]glucose method described by Sokoloff et al. Nicotine was administered in 3 dosages: 0.5 microgram/kg/min, 1.58 micrograms/kg/min and 5 micrograms/kg/min. The resulting plasma concentrations of nicotine were 10/39/114 ng/ml plasma. During the experiment, blood pressure, heart rate, body temperature, hematocrit, acid-base status and plasma glucose concentration showed no--or minor--changes. Nicotine significantly increased LCGU in a dose-dependent manner in the following 9 of 45 examined structures: substantia nigra (compact part), superior colliculus (superficial grey layer), interpeduncular nucleus and cingulate cortex (P less than 0.01); lateral geniculate body, optic chiasm, anteroventral and anteromedial nucleus of thalamus and mamillary body (P less than 0.05). For most of these structures with increased LCGU, other groups have reported a high regional receptor binding of nicotine (exception: mamillary body and optic chiasm). It is concluded that nicotine has distinct effects on the functional activity of localized brain areas.