The peptidic hormone leptin, also known as OB protein, plays an important role in regulating body mass, as well as influencing food intake and energy balance within the body of rodents and humans (Stosberg and Tarik 1999; Campfield et al. 1996). Leptin also plays a major role in determining the fertility status of the rodent or individual (Israel and Chua 2009). In order to be fertile one has to go through puberty (Stosberg and Tarik 1999). In order to begin puberty one has to have sufficient energy (balance) and a functioning hypothalamus; a gland found within the brain which is responsible for releasing reproductive hormone gonadotropin-releasing hormone(GnRH) (Stosberg and Tarik 1999; Israel and Chua 2009). The role of leptin is to first…show more content… In order to activate puberty, one needs a minimum amount of body fat and therefore energy; however, it is unknown as to how information indicating that this energy requirement is met and sent to the brain (Stosberg and Tarik 1999). The discovery of the OB protein pathway, which is essentially a communication link between adipose tissue and the brain, plays a crucial role in energy balance (Campfield et al. 1996). It may be the mechanism that allows and makes leptin to be a good candidate for informing the brain that sufficient energy requirement for puberty has been met (Stosberg and Tarik 1999). It was observed that test rodents and human patients, with a mutation to the leptin and leptin receptor, genes were all infertile (Stosberg and Tarik 1999). On the other hand, individuals who suffer from overall low body fat percentage were also found to be infertile; further observation of these individuals revealed low leptin concentration within their bodies (Stosberg and Tarik 1999). Mutation of leptin and leptin receptors upsets the energy balance of the body which causes…show more content… In mice, data has shown leptin plays a major role in developing areas of the hypothalamus that control energy balance (Coll et al. 2007). This development is specifically important as it influences energy balance later in life (Coll et al. 2007). As stated previously, a minimum amount of “fat” or energy is required to initiate puberty (Stosberg and Tarik 1999). Additionally, increase in gonadotropin-releasing hormone (GnRH), secreted by the hypothalamus, regulates the hormones, follicle stimulating hormone and luteinizing hormones, that initiate puberty (Stosberg and Tarik 1999). Leptin indirectly influences the release of GnRH hormones by again influencing such neurons as kisspeptin (Israel and Chua 2009). When leptin binds to this kisspeptin neurons it promotes the release of GnRH. However, when leptin receptors are not available, GnRH stimulation decreases and causes infertility among rodents and humans (Israel and Chua 2009). Overall, mutations of leptin and leptin receptor causes infertility by influencing the development of the hypothalamus, which plays a vital role in puberty, and the amount of hormones it secretes (Israel and Chua 2009; Coll et al. 2007).
Lastly, experiments on obese mice who were also infertile, due to leptin and leptin receptor mutations were given leptin supplements (Coll et al. 2007). The addition of leptin to
