Dr David McGrath

Spine Physician

MB BS (Hons) FAFOM, RACP, FAFMM
Master of Pain Medicine

Membrane Physiology

Membranes are the interface between cells and the world. There are also internal membranes, encapsulating the cell nucleus, mitochondria and other organelles, such as microsomes (ancient captured bacteria)

They are composed of the following components:
1. Phospholipids (double layer )
2. Cholesterol
3. Sphingolipids
4. Proteins
The lipids attached to the phospholipids/sphingolipids are either saturated or unsaturated.Unsaturated lipids can be either:
1. Omega6
2. Omega3

The membrane has physiological properties essential for healthy cell function.
1. Impermeability to water soluble chemicals
2. Stiffness (decreases with polyunsaturated lipids) (increases with cholesterol content)

Possible associations between membrane composition and health
1. Low levels of serum cholesterol associated with depression and increased suicide risk
2. Increase in omega6/omega3 ratio in RBC (red blood cell) with major depression
3 More inflammatory markers when omega6/omega3 high (these are precursors to the cytokines and eicosanoids)

(to be continued )