Leptin is the protein hormone produced by adipose tissue.
Leptin: The Adipose Tissue Hormone
Adipose tissue, commonly known as body fat, is not just an energy storage site; it's also an active endocrine organ that produces various hormones. One of the most well-known hormones released by adipose tissue is leptin. This peptide hormone plays a crucial role in regulating energy balance within the body.
Key Characteristics of Leptin
- Source: Leptin is synthesized by white adipose tissue.
- Gene Location: The LEP (or ob) gene, which encodes for leptin, is located on chromosome 7q31.3.
- Structure: The mature leptin protein consists of 146 amino acids.
- Production: Leptin is produced via mRNA-directed protein synthesis.
- Function: Leptin acts primarily on the hypothalamus in the brain to regulate appetite and energy expenditure. It signals the brain about the body's energy reserves, promoting a feeling of satiety when energy stores are sufficient and encouraging food intake when stores are low.
How Leptin Works
Leptin circulates in the bloodstream and binds to leptin receptors located in various tissues, including the hypothalamus. This interaction helps to regulate:
- Appetite: It decreases appetite by signaling satiety to the brain.
- Energy Expenditure: It increases energy expenditure by influencing metabolic rate.
- Hormonal Balance: Leptin interacts with other hormonal pathways, affecting reproductive function and insulin sensitivity.
Practical Insights
- Obesity and Leptin: In some cases, obesity is associated with leptin resistance, where the body does not respond effectively to leptin signals. This is a complex area of research.
- Therapeutic Potential: Research is ongoing into the therapeutic potential of leptin and its analogues for treating obesity and related conditions.
- Leptin Levels: Leptin levels are generally proportional to the amount of body fat.
| Feature | Details |
|---|---|
| Hormone | Leptin |
| Source | White adipose tissue |
| Gene | LEP (ob), chromosome 7q31.3 |
| Structure | 146 amino acids |
| Function | Regulates appetite, energy expenditure |
| Production | mRNA-directed protein synthesis |
In summary, leptin is a key protein hormone produced by adipose tissue that plays a critical role in energy balance.
