What is glycation?
As the reaction glycation of proteins, lipids, nucleic acids or carbohydrates without the involvement of enzymes is called. The enzymatic reaction against it is called glycosylation. A glycation can be done exogenous or endogenous, ie outside or inside the body.
Exogenous glycation
Exogenous glycation usually occurs when proteins with sugars are cooked. Temperatures above 120 ° C promote this process. The reaction product is referred to as Advanced glycation end product (AGE). The glycation by dry cooking methods with reducing sugars is called the Maillard reaction, some of the resulting colored reaction products are among the melanoidins. AGEs are used in the food industry as a flavor enhancer, dyes, or for the improvement of the appearance. Originally, it was believed that AGEs are harmless. Recent research, however, suggests that AGEs in some diseases are at least involved. Furthermore, glycation may also be involved in the formation of acrylamide. In general, however, the concentration of AGEs in food unzubereiteten not worrying. However, concentrations can be achieved in particular by frequent consumption of fried and grilled food that can be neutralized by the body no longer, like this is generally the case in advanced age.
Endogenous glycation
Endogenous glycation is also produced in the body, particularly in the bloodstream. This response essentially fructose and galactose, and to a lesser extent uncontrolled glucose with endogenous proteins without the involvement of enzymes. As a result of the metabolism reactive dicarbonyls such as 3-deoxyglucosone and methylglyoxal. The problem here is the accumulation of AGE over time, particularly at an elevated blood glucose level, can be damaged in which cells and tissues.
In the glycation of hemoglobin HbA1c arises. The HbA1c share of hemoglobin can be measured, for example, estimate the average blood glucose level over the past four to twelve weeks in diabetics.
Health effects
The endogenous glycation is attributed to participate in different age-related diseases, such as Type II diabetes mellitus and cardiovascular disease. Higher concentrations of AGE formed, for. Example by oxidative stress or hyperglycemia. They are associated with atherosclerosis, among other things, a worse angiogenesis and an impaired wound healing. Some AGE promote inflammation, in part, by binding to the cellular receptor Receptor for AGE (RAGE) on monocytes. The activated during an AGE-induced inflammatory monocytes secrete interleukin-1, TNF-α, platelet derived growth factor and insulin-like growth factor-1. Furthermore, this platelets are activated, which can form blood clots increases. As a result of glycation may in neurons lead to a degradation of myelin and neuropathies, eg. As in type II diabetes mellitus and Alzheimer's disease. Furthermore, a participation in osteoporosis, glomerulosclerosis, arthritis, respiratory failure and sepsis is investigated.