This module dives into the physiological features of albumin.
Learners will come to understand the structure of this abundant protein, how it is synthesized, and its circulatory half-life, as well as be introduced to its oncotic and non-oncotic functions.
For a deeper dive into albumin’s oncotic and non-oncotic functions, view the Albumin as a Plasma Expander – Oncotic Properties and Non-Oncotic Properties modules.
Key Takeaways
Albumin is a small globular protein synthesized by the liver and represents the most abundant circulating protein in human plasma.
Many endogenous factors can increase its production by the hepatocytes (e.g., insulin, cortisol and growth hormone) while others can inhibit its synthesis (various pro-inflammatory cytokines).
The circulatory half-life of albumin is about 16-18 hours, and its total half-life is 12-19 days.
The normal laboratory range of albumin is between 3.5 and 5.0 g/dl, but large observational studies demonstrated that physiological serum albumin levels in healthy subjects are above 4.0 g/dl.
Albumin secondary molecular structure is characterized by α-helices, while its tertiary structure is stabilized by 17 disulfide bridges among couples of Cysteine residues.
The regulation of fluid distribution is the main oncotic property of albumin. The molecule also plays many biological non-oncotic functions.
