What is the function of albumin in blood?

Albumin is the most abundant protein in blood plasma, accounting for approximately 60% of total plasma protein.

Here are the primary functions of albumin in blood:

1. Maintenance of Colloid Osmotic Pressure:

- Albumin is responsible for maintaining the colloid osmotic pressure or oncotic pressure of blood.

- Colloid osmotic pressure helps retain water in the circulatory system, preventing fluid from leaking out into the tissues.

- Maintaining proper fluid balance is crucial for preventing edema (swelling due to fluid accumulation) in body tissues.

2. Transport of Substances:

- Albumin functions as a carrier for various substances in the blood. It binds to and transports hormones, drugs, fatty acids, vitamins, metal ions, and other molecules throughout the body.

- For example, albumin binds to steroid hormones and thyroid hormones, helping regulate their distribution and activity.

3. Buffering Capacity:

- Albumin can bind to hydrogen ions (H+), contributing to the acid-base balance in the blood. It acts as a buffer against pH changes, helping maintain the appropriate pH range for optimal functioning of enzymes and cellular processes.

4. Protection Against Oxidative Stress:

- Albumin possesses antioxidant properties. It can bind to and neutralize free radicals, which are highly reactive molecules that can cause damage to cells and tissues if not controlled. By scavenging free radicals, albumin helps protect against oxidative stress and reduces the risk of various diseases associated with oxidative damage.

5. Modulation of Immune Function:

- Albumin plays a role in modulating the immune response. It can bind to and transport immune molecules such as antibodies, aiding in the targeted immune response against antigens. Additionally, albumin can bind to and suppress certain inflammatory mediators, contributing to the regulation of immune reactions.

Overall, albumin's functions are critical for maintaining fluid balance, facilitating the transport of various substances, regulating pH, protecting against oxidative damage, and influencing immune responses in the body.