Which protein is primarily involved in regulating fluid balance in the body?

The primary protein involved in regulating fluid balance in the body is albumin. Albumin is produced in the liver and accounts for a significant part of the total protein content in plasma. It plays a crucial role in maintaining oncotic pressure, which is the pressure exerted by proteins in the blood plasma that helps to keep fluid within the circulatory system and prevent it from leaking into surrounding tissues.

By retaining fluid within the blood vessels, albumin helps to ensure that the body maintains proper hydration levels and supports cardiovascular function. This regulation of fluid balance is vital for overall homeostasis.

Globulin is involved in immune functions and transport of proteins, while collagen primarily serves structural purposes in connective tissues, not fluid regulation. Keratin is a structural protein found in hair, nails, and skin, and is not involved in fluid balance. Therefore, albumin stands out as the key protein that directly influences fluid distribution and balance in the body.