Scientific Facts About Alpha-Ketoglutarate
1-) AKG additional nutritional supplement increases the levels of insulin, growth hormone and IGF-1 (Insulin-like growth hormone) (4,5).
2-) ABG increases iron absorption (8).
3-) AKG is a helpful element in bone growth and health.
4-) AKG ; Since it increases the synthesis of nitric oxide, it has the ability to expand the vessels.
AKG Definition and Mechanism
Alpha-ketoglutarate ( AKG ); It is an intermediate product produced in the tricarboxylic acid (TCA) cycle (aka Krebs cycle; the second stage of cellular aerobic respiration after the glycolysis stage) and plays an important role in energy metabolism. AKG ; In the TCA cycle, it turns into succinylCoA as a result of carbon dioxide removal with the help of AKG -Dehydrogenase enzyme. This stage is a very important point in the TCA cycle (1).
It can be obtained from Isocitrate by oxidative decarbonization, as well as from glutamate by oxidative deamination and by the help of pyridoxal phosphate dependent transamination. AKGIt is much better absorbed from the upper parts of the intestine and has a short duration of action. This is probably due to the rapid metabolism that takes place in the enterocyte (intestinal cell) and liver (2).
In addition, AKG ; enterocytes are converted to proline, leucine and other amino acids (3).
In addition, AKG supplementation increases the levels of insulin, growth hormone and IGF-1 (Insulin-like growth hormone) (4,5).
AKG ; It is also a source of glutamine and glutamate , which trigger protein synthesis in cellular metabolism , prevent muscle protein breakdown after sports or during fasting, and form an important energy source for digestive system cells (6).
Glutamine is an important nutritional source for all cell types and makes up more than 60% of the amino acid pool. Based on this , AKG , which is the precursor of glutamine ; It is the main energy source of intestinal cells and the most preferred substrate for enterocytes and other rapidly dividing cells. It also provides the synthesis of glutamate, which is secreted from nerve fibers in the bone tissue (7).
In recent studies, AKG has been shown to increase iron absorption. Therefore, AKG and its derivatives may play a preventive role against iron deficiency in individuals who are in development (2).
In addition, AKG is an important source of amino acids needed for collagen synthesis in cells and organisms, and therefore supports bone tissue (8). Glutamine and glutamate are converted to ornithine and arginine . Ornithine and arginine also stimulate the secretion of growth hormone and IGF-1. Growth hormone and IGF-1 have positive effects on bone tissue (9).
Glutamine is an important energy source for macrophage and lymphocyte cells that protect the body against dangerous infections such as sepsis (blood poisoning). Since it plays an important role in glutamine synthesis in AKG , it ensures that the immune system is strong.
In a study , in order to understand the effects of ABG on skeletal muscle hypertrophy; 1% and 2% AKG supplements were given to laboratory rats along with water . When compared to the control group, it was observed that the amount of serum ABG was higher in the 2% group . In addition; 2% ABGIt was observed that abdominal adiposity decreased and the weight of the calf muscles increased in the group receiving the supplement .
At the same time , genes that cause protein degradation in leg muscles were significantly less active in the 2% group. As a result; especially due to the increase in leg muscle mass and protein synthesis, AKG has positively affected the hypertrophy process (10).
ABG Definition and Effect
It consists of arginine alpha-ketoglutarate and alpha ketoglutaric acid. It is one of the intermediates of nitric oxide metabolism. AKG taken as additional food ; emphasis is placed on blood pressure, heart rhythm, and the dilating effect on the vessels. The expansion of the vessels as a result of the rise of nitric oxide will theoretically help the nutrients reach the tissues much faster and easier.
According to a study conducted in 2006, an increase was observed in 1RM (one rep with maximum weight) strength and Wingate performance tests of individuals given 4 g of AKG supplementary food. In the same test, it was observed that there was no extra contribution to aerobic exercises (11).
AKG More research is needed to obtain clearer information about the effect of .
Sports Dietitian Coşku HAPPY
1-) Nan Wu , Mingyao Yang , Uma Gaur , Huailiang Xu , Yongfang Yao , and Diyan Li * Alpha-Ketoglutarate: Physiological Functions and Applications. Biomol Ther (Seoul) . Jan 2016; 24(1): 1–8.
2-) Dąbek M, Kruszewska D, Filip R, Hotowy A, Pierzynowski Ł, Wojtasz-Pająk A, Szymanczyk S, Valverde Piedra J, Werpachowska E, Pierzynowski S. α-Ketoglutarate (AKG) absorption from pig intestine and plasma pharmacokinetics. J Anim Physiol Anim Nutr. 2005;89:419–426. doi: 10.1111/j.1439-0396.2005.00566.x.
3-) Lambert BD, Filip R, Stoll B, Junghans P, Derno M, Hennig U, Souffrant WB, Pierzynowski S, Burrin DG. First-pass metabolism limits the intestinal absorption of enteral α-ketoglutarate in young pigs. J Nutr. 2006;136:2779–2784.
4-) Colomb V, Dabbas M, Goulet O, Talbotec C, Corriol O, Ricour C. Prepubertal growth in children with long-term parenteral nutrition. Horm Res Paediatr. 2004;58:2–6. doi: 10.1159/000064760.
5-) Son ED, Choi GH, Kim H, Lee B, Chang IS, Hwang JS. Alpha-ketoglutarate stimulates procollagen production in cultured human dermal fibroblasts, and decreases UVB-induced wrinkle formation following topical application on the dorsal skin of hairless mice. Biol Pharm Bull. 2007;30:1395–1399. doi: 10.1248/bpb.30.1395.
6-) Jones C, Allan Palmer T, Griffiths R. Randomized clinical outcome study of critically ill patients given glutamine-supplemented enteral nutrition. Nutrition. 1999;15:108–115. doi: 10.1016/S0899-9007(98)00172-5.
7-) Stoll B, McNelly S, Buscher HP, Häussinger D. Functional hepatocyte heterogeneity in glutamate, aspartate and α-ketoglutarate uptake: A histoautoradiographical study. hepatology 1991;13:247–253. doi: 10.1002/hep.1840130208.
8-) Tocaj A, Filip R, Lindergard B, Wernerman J, Studzinski T, Ohman K, Pierzynowski S. Alpha-ketoglutarate (AKG) inhibitor osteoporosis development in postmenopausal women; Journal of Bone and Mineral Research; 2003. pp. S267–S267. Amer Soc Bone & Mineral Res 2025 M St, Nw, Ste 800, Washington Dc 20036-3309 USA.
9-) Fayh AP, Friedman R, Sapata KB, Oliveira AR. [Effect of L-arginine supplementation on secretion of human growth hormone and insulin-like growth factor in adults] Arq Bras Endocrinol Metabol.2007;51:587–592. doi: 10.1590/S0004-27302007000400013.
10-) Xingcai Cai ,1,* Canjun Zhu ,1,* Yaqiong Xu ,1 Yuanyuan Jing ,1 Yexian Yuan ,1 Lina Wang ,1 Songbo Wang ,1 Xiaotong Zhu ,1 Ping Gao ,1 Yongliang Zhang ,1 Qingyan Jiang , a,1,2 and Gang Shub,1,2 Alpha-ketoglutarate promotes skeletal muscle hypertrophy and protein synthesis through Akt/mTOR signaling pathways. Sci Rep . 2016; 6: 26802.
11) Campbell B 1, Roberts M , Kerksick C , Wilborn C , Marcello B , Taylor L , Nasser E , Leutholtz B , Bowden R , Rasmussen C , Greenwood M , Kreider R . Pharmacokinetics, safety, and effects on exercise performance of L-arginine alpha-ketoglutarate in trained adult men. Nutrition. 2006 Sep;22(9):872-81.