Lithium and methylphenidate: opposite effects on perirenal brown fat

objective: to evaluate the effects of the administration of lithium to adult rats on brown (perirenal) and white (inguinal) adipose tissues and to assess whether methylphenidate modulates lithium effects. methods: twenty-five adult male wistar rats were fed with either regular or lithium-containing chow for 30 days. between days 15 to 30 of treatment, animals received daily intraperitoneal administrations of either methylphenidate or saline. results: lithium significantly reduced perirenal fat, and this effect was minimized by the administration of methylphenidate. there were no significant differences between the groups in terms of the effects of lithium on inguinal fat. conclusion: our findings suggest that different effects on white and brown tissue distribution may be involved in lithium-induced weight gain.