Final answer:
Leptin, secreted by adipose tissues, regulates appetite by promoting satiety. It has a role in energy balance and reproduction. Leptin resistance, often seen in obesity, disrupts this regulation leading to overeating and associated health risks.
Step-by-step explanation:
Leptin is a hormone produced by adipose tissues (fat cells) that plays a crucial role in regulating energy balance by inhibiting hunger, which leads to appetite suppression. When fat reserves are ample, adipose tissue releases more leptin, signaling the brain to reduce food intake. In contrast, low fat reserves result in decreased leptin production, which can increase hunger. Obesity can disrupt this process through a condition known as leptin resistance, where despite high leptin levels due to excess fat, the brain fails to recognize satiety, leading to overconsumption and weight gain.
Leptin resistance is a significant factor in the pathophysiology of obesity and associated health risks. It is also essential for reproduction; without sufficient body fat and the resultant leptin release, reproductive hormones such as gonadotropin-releasing hormone (GnRH) and gonadotropins would not be produced, affecting fertility.