As in other body tissues, the cells in the skin need energy to maintain their vital functions and their ability to regenerate and repair themselves as well as to grow. This energy is generated during intracellular metabolic processes.
Dermal blood (i) flow supplies the basal cells with nutrients like fats (i), carbohydrates, proteins and oxygen. Free fatty acids, if in sufficient supply, play the largest role in energy production in skin cells. Cells like those in the stratum granulosum - into which little glucose diffuses – seem to use even the fatty acids set free during degradation of the cell membrane to produce energy.
Methods of energy production
Energy is produced by cells in three ways:
- Citrate cycle
- Respiratory chain
Glycolysis takes place in the cytoplasm and is a quickly activated form of energy production. The stages of the citrate cycle and respiratory chain (i) also known as biological oxidation proceed in the cell mitochondria.
The respiratory chain (i) - the master energy producer
The most energy is produced in the respiratory chain (i). All enzymatic degradation processes of fats (i), carbohydrates and amino acids end in this third stage of aerobic metabolism. The electron transport system of the respiratory chain (i) plays a central role. Certain proteins localized almost exclusively in the inner mitochondrial membrane function as electron carriers.
Substances like the NAD(P)-dependent dehydrogenases, ubiquinone (coenzyme Q10) or the cytochromes act as collecting points for reducing equivalents or as electron carriers. The energy released along the electron chain is stored as chemical energy in the form of adenosine triphosphate (ATP).
Skin aging and a special electron carrier
More recent findings show that a deficiency of a certain enzyme, coenzyme Q10 (CoQ10), in the respiratory chain (i) plays an important role in the reduced cell regeneration capacity resulting from aging or oxidative stress. Patients with cardiovascular disease often take Co Q10 orally to make up for this deficiency.
A biophysical study has now shown for the first time that topical application of CoQ10 can also reduce signs of skin ageing.
The third stage of metabolism, the respiratory chain (i), plays an important role in energy production. It could be shown in a biophysical study that coenzyme Q10, which acts as an electron carrier and collecting point for reduction equivalents, reduces the signs of skin aging when applied topically.