Canonical Question
IV Fluids
Master answer
Physiology of Albumin
| ALBUMIN | |
| DEFINITION | A naturally occurring protein found in blood plasma. Recombinant human albumin is a product that is manufactured to be structurally equivalent to native human serum albumin. |
| CLASSIFICATION | 6 subfamilies – vit D binding proteins occupy family 1-2 |
| SYNTHESIS | In liver |
| Synthesized as preproalbumin → N-terminal peptide removed → proalbumin → cleared in Golgi vesicle → albumin | |
| FACTORS AFFECTING SYNTHESIS | Nutrition |
| Liver function | |
| infection /sepsis/inflammation | |
| DISTRIBUTION | 40% intravascular space 60% extravascular space |
| The balance between plasma and interstitial space is established at varying rates with respect to the two subcompartments of the extravascular albumin pool | |
| Factors affecting distribution: HTN, CCF, trauma, exercise, DM, Burns, CPB | |
| BREAKDOWN | Broken down by cysteine protease |
| Elimination half life – 16hrs | |
| FUNCTIONS OF ALBUMIN | |
| Osmotic pressure | supplies 80% of total plasma Colloid Osmotic Pressure |
| retards fluid efflux from plasma and oedema formation | |
| Transport and metabolism functions | Transports thyroid hormones |
| Transports other hormones, in particular, ones that are fat-soluble | |
| Transports fatty acids (“free”) to the liver and to myocytes for utilization of energy | |
| Transports unconjugated bilirubin | |
| Transports many drugs; serum albumin levels can affect the half-life of drugs | |
| Buffer | Extra-cellular acid-base buffer |
| Detoxification | solubilizes bilirubin and neutralizes its toxic effects |
| Anti-oxidant effects | Blocks Cu2+-mediated LDL oxidation |
| Blocks Free-radical-mediated haemolysis | |
| Anticoagulant effect | |
| Protein store | for signalling molecules and nitric oxide |
| Immunomodulation | |
| Other | Competitively binds calcium ions (Ca2+) |
| Prevents photodegradation of folic acid | |
| marker of an inflammatory state | |
| prevents apoptosis of proximal renal tubular cells | |
| stimulates proliferation of proximal renal tubular cells | |
| MANUFACTURING PROCESS | |
| Source | From Aus-sourced plasma Pooled from thousands of donations (minimises the infection risk) |
| Whole plasma is fractionated to prepare Albumin | |
| Fractionation | Physical separation (by precipitation) |
| Chromatography (separates molecules based on chemical and physical properties | |
| Removal of pathogens by: – Pasteurisation (vapour heat 60C for 10hrs) – Use of solvents and detergents – Exposure to low pH conditions – Nanofiltration | |
| Partitioning | allows purification of immunoglobulins, clotting factors and albumin from plasma |
| Storage | stored in secure & monitored environments |
Pharmacology of Albumin
CICMWrecks Table – Albumin (Click to Open)
Guo / JC 2021
Exam appearances
| Exam | Exact wording | Relationship | Success |
|---|---|---|---|
| 2020B Q12 | Describe the physiology (50% marks) and pharmacology (50% marks) of albumin. | historical_member | — |