Sex differences in nicotine's effects on consummatory behavior and body weight in rats

Nicotine administration and cessation have greater effects on body weight and eating behavior in female than in male rats. These generalizations are based on studies of body weight and eating behavior for 2-3 week periods before, during, and after nicotine administration. Therefore, the sex differences may reflect differences in sensitivity to nicotine or simply differences in the time course of nicotine's effects. The present research was designed to replicate these previous studies and to examine long-term effects of nicotine cessation on body weight. Nicotine or saline was administered SC to female and male Sprague-Dawley rats for 16 days. Body weight, food consumption, and water consumption were measured before, during, and after nicotine administration. In addition, body weight was measured for 4 months after cessation of nicotine. There was an inverse relationship between nicotine and body weight. Also, there was an inverse relationship between nicotine and general consummatory behavior for females but not for males. The body weight of females that had received nicotine were indistinguishable from controls up to 4 months after cessation of nicotine. The body weight of males that had received 12 mg nicotine per kg per day remained lower than controls.