Changes in leptin production/secretion induced in response to septic doses of lipopolysaccharides in gonadally intact and ovariectomized female rats

In addition to its role as a regulator of energy homeostasis, leptin plays a pivotal role in certain immune/inflammatory responses. It has been reported that the synthesis and secretion of leptin are increased during immune stress in male experimental animals, whereas the changes in leptin synthesis and secretion induced by immune stress in females have not been fully elucidated. In this study, we found that during lipopolysaccharide (LPS)-induced immune stress the synthesis and secretion of leptin were decreased in gonadally intact female rats, but increased in ovariectomized rats. However, the LPS-induced increase in the serum leptin level observed in the ovariectomized rats was partially attenuated by estradiol supplementation. These results suggest that the changes in leptin synthesis and secretion induced in response to immune stress in females are affected by the gonadal steroid milieu and that estradiol and other factors are involved in these alterations.