Adipose tissue, commonly known as body fat, secretes several hormones that play vital roles in regulating various bodily functions, particularly metabolism. These hormones are known as adipokines. According to the provided reference, the main hormones secreted by adipose tissue include leptin, adiponectin, and resistin.
Key Adipokines Secreted by Adipose Tissue
| Hormone | Main Function |
|---|---|
| Leptin | Primarily involved in regulating energy balance by signaling satiety to the brain, reducing appetite, and increasing energy expenditure. |
| Adiponectin | Enhances insulin sensitivity, has anti-inflammatory properties, and plays a role in glucose and lipid metabolism. It also helps protect against cardiovascular diseases. |
| Resistin | While not directly produced by human adipocytes, but by macrophages within adipose tissue, it is associated with insulin resistance and inflammation. It's expression and function is very similar in mice and humans. |
Detailed Look at Each Hormone
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Leptin: This hormone acts as a signaling molecule to the brain, indicating the amount of fat stored in the body. Higher fat stores lead to increased leptin secretion, which ideally suppresses appetite. In obesity, however, this signaling can become less effective leading to leptin resistance.
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Adiponectin: Known for its anti-diabetic and anti-inflammatory effects, adiponectin helps improve insulin sensitivity and reduce the risk of type 2 diabetes. Higher levels of adiponectin are generally associated with better metabolic health, and they can improve glucose uptake, and reduce inflammation.
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Resistin: Resistin's function is complex and somewhat controversial. In mice, it causes insulin resistance, but the role of resistin in human physiology is not as clear. However, it is associated with inflammation and insulin resistance in humans, though produced by immune cells within adipose tissue and not the fat cells themselves.
Summary
Adipose tissue is an active endocrine organ that plays a crucial role in maintaining metabolic health by secreting several hormones like leptin, adiponectin, and resistin. While resistin is produced by macrophages within adipose tissue and not directly from the adipocytes in humans, it shares similar functionality in both mouse and humans. These hormones are vital for regulating energy balance, glucose metabolism, and inflammation. The dysregulation of these hormones is often linked to metabolic disorders like obesity and type 2 diabetes.
