What is the Difference Between Leptin and Ghrelin

The main difference between leptin and ghrelin is that leptin decreases the appetite, whereas ghrelin increases the appetite.

Leptin and ghrelin are two hormones that control appetite and fullness. They help to regulate body weight.   

Key Areas Covered

1. What is Leptin
– Definition, Structure, Function
2. What is Ghrelin
– Definition, Structure, Function
3. Similarities Between Leptin and Ghrelin
– Outline of Common Features
4. Difference Between Leptin and Ghrelin
– Comparison of Key Differences

Key Terms 

Ghrelin, Leptin

What is Leptin

Leptin is a hormone released to maintain normal body weight long-term. The body fat is related to the levels of leptin in the body. Also, fatty tissue of the body releases the hormone leptin. Leptin regulates the long-term balance between food intake and energy use. It prevents hunger response when it does not need energy in the form of calories. Additionally, it acts on the brainstem and hypothalamus to avoid hunger.

Figure 1: Leptin

Furthermore, leptin does not regulate hunger from meal to meal. It only regulates appetite in the long term. Leptin resistance causes feeling hungry and eating more even though the body has enough fat stores. Notably, leptin has a profound effect while losing weight. When losing body fat, the amount of leptin decreases. It stimulates intense hunger and appetite, which in turn increases food consumption. 

What is Ghrelin

Ghrelin is a hormone produced and secreted by the stomach. When the stomach is empty, ghrelin signals the brain to eat. The levels of ghrelin increase when the stomach is empty and decrease when the stomach is full. People who have obesity have low levels of ghrelin. Also, people who reduce their calorie intake have high levels of ghrelin. The small intestine, brain, and pancreas produce small amounts of ghrelin. Often, ghrelin is called the hunger hormone. It increases the food intake allowing the body to increase fat stores. Also, it stimulates the pituitary gland to secrete growth hormones.

Figure 2: Leptin and Ghrelin Function

Moreover, ghrelin controls the sugars in the body. It controls the release of insulin. Also, it has a role in protecting muscles from weakness. It allows the bone formation and metabolism of the body. Additionally, ghrelin signals the hypothalamus to increase appetite. It promotes fat stores. Also, it stimulates the GI tract to move food through small and large intestines. It has a role in protecting the cardiovascular system. 

Similarities Between Leptin and Ghrelin

• Leptin and ghrelin are two hormones that control appetite and fullness by signaling.
• They help to regulate body weight. 

Difference Between Leptin and Ghrelin

Definition

Leptin is a protein produced by fat cells and is a hormone that regulates appetite and fat storage. In contrast, ghrelin is a peptide hormone produced mainly in the stomach and increases appetite by stimulating the pituitary gland to secrete growth hormone.

Significance

Leptin decreases the appetite, while ghrelin increases the appetite.

Production

The adipose tissue produces leptin, while the stomach produces ghrelin. 

Effector Gland

Leptin stimulates the brainstem and hypothalamus, while ghrelin stimulates the pituitary gland.

Structure

Leptin is a protein, while ghrelin is a peptide.

Length

Leptin composes 167 amino acids in a long chain with four helical assemblies, while ghrelin contains 28 amino acid peptides. 

Function

Leptin regulates the long-term balance between food intake and energy use, while ghrelin stimulates food intake, fat deposition, and growth hormone release.  

Conclusion

In brief, leptin and ghrelin are two hormones that control the appetite and fullness of the body. Leptin is a protein that composes of 167 amino acids long chain. It regulates the long-term balance between food intake and energy use. Therefore, it decreases the appetite. In comparison, ghrelin is a peptide hormone that contains 28 amino acids. Also, it stimulates food intake, fat deposition, and growth hormone release. Therefore, it increases appetite. Hence, the main difference between leptin and ghrelin is their structure and function. 

References:

1. Leptin: What it is, Function & Levels. Cleveland Clinic. 
2. Ghrelin hormone: Function and definition. Cleveland Clinic. 

Image Courtesy:

1. “Leptin2” By Lijealso – Own work (CC-BY 3.0) via Commons Wikimedia
2. “Lijealso” By Injurymap – Own Work (CC-BY 2.0) via Commons Wikimedia