Levocarnitine in pediatric practice
Currently, in pediatrics and pedopsychiatry there is a relentless search for adequate methods of treatment and prevention of neuropsychiatric disorders of children, especially at an early age. In particular, such therapy methods include the use of ergotropic drugs, the active principle of which is levocarnitine (L-carnitine), akin to the B vitamins.
As presented in the reviews of I.L. Brina, V.M. Cousin
and other authors, carnitine was discovered in 1905 by Russian scientists V.S. Gulevich and R. Krinberg, who discovered it in the tissues of the striated muscles of mammals, and in the 1950s. established its vitamin-like effect. Carnitine was first synthesized in 1960. Later it was found that the metabolic functions of carnitine are associated with the transport of long chain fatty acids through the internal
mitochondrial membrane, their subsequent oxidation and release of ATP energy, modulation of intracellular coenzyme A homeostasis in the mitochondrial matrix, detoxification of excess acetic and a number of other organic acids, as well as participation in the process of glycolysis, the exchange of ketone bodies and choline. So important in the metabolism of fats, glucose, amino acids and in energy production, carnitine can be attributed to irreplaceable substances.
One of the main functions of carnitine is the transport of fatty acids through the membranes of intracellular organelles, in which they are oxidized with the formation of energy and “building materials” necessary for the development of the nervous system of a growing organism, especially the fetus. In the environment where the fetus develops, which is poor in oxygen and glucose, fatty acids are the main source of energy, because, unlike glucose, they can be oxidized at low oxygen levels in the blood, but require a large amount of carnitine. Therefore, the synthesis and need for carnitine in the fetus is observed in increasing progression.
The importance of carnitine for the growth and development of the child
In the works of O.A. Baranova and T.Yu. Savirova also emphasizes the importance of carnitine for the baby’s body in the prenatal period and in the first years of life. With his participation, the brain and spinal cord are formed, their growth continues, the interaction of all parts of the nervous system responsible for muscle movements and interaction is improved. The more pronounced carnitine deficiency is, i.e., the synthesis and transport of carnitine in general and to the affected area of the brain in particular are impaired, the more severe motor disorders (from paralysis to hyperkinesis).
Carnitine deficiency can be caused by genetic disorders (primary failure, 1 case per 40-100 thousand people) or some medical conditions (secondary failure, in particular, with chronic kidney disease or with some antibiotics). In humans and animals, levocarnitine is synthesized from γ-butyrobetaine under the action of the enzyme γ-butyrobetaine hydroxylase (dioxigenase) in the liver and kidneys, from which it is transported to other tissues and organs. In young children, endogenous synthesis of carnitine is practically not carried out, since the activity of γ-butyrobetaine hydroxylase in newborns is only 12.0% of its level in adults; and the latter is achieved only by 15 years of life. This makes babies more vulnerable to deficiencies in the exogenous intake of carnitine with food (especially animal protein) that half the amount of need for carnitine. All this necessitates the use of additional sources of this substance. Primary systemic carnitine deficiency (carnitine transporter deficiency) is a hereditary pathology characterized by severe metabolic disorders caused by impaired absorption of carnitine from food. The clinic of the disease was described in 1975 by Carpathi. The mechanism of disease inheritance is autosomal recessive, pathology is observed with equal frequency in both men and women. In 1998, it was found that the primary systemic carnitine deficiency is due to mutations in the SLC22A5 gene, which is located on the 5th chromosome. It encodes the sequence of the protein OCTN2, which is a transporter of carnitine, as a result of which carnitine coming from food is not absorbed by the body. In other words, energy starvation of tissues and organs occurs, in which violent biochemical processes occur.
The clinical manifestations of carnitine deficiency depend on the form of pathology – in patients, appetite disorders, hepatomegaly, central nervous system (CNS) and heart lesions can be detected. There are two main clinical forms of primary systemic carnitine deficiency – metabolic and cardiomyopathic. With a metabolic variety, the first symptoms of the disease appear very early – usually during the first two years of a child’s life, until this moment an increased frequency of infectious lesions of the upper respiratory tract is recorded.