L.A. Kovalchuk, L.V. Chernaya, E.S. Nokhrina

The medical leech (Hirudo medicinalis) is one important biological resources of water areas in Russia. It is used in hirudotherapy, besides. its tissue homogenates are a raw material for pharmaceutical and cosmetic production. Presently many biologically active compounds of protein nature have been discovered in its tissues. However, the data on the levels of such important components as macro- and microelements, free amino acids, at various physiological conditions are insufficient. Considering the fact that the leech is capable to starve over a year, a research on the levels of biologically active compounds (BAS) in its tissues at various terms of starvation are actual. We investigated the levels of trace elements and the amino acid pool in tissues of the medicinal leeches during starving for three, five, seven or twelve months were investigated. In the tissues of the leeches concentrations of Cu, Zn, Mn, Ca, Mg, Co, Sr, Cd and Pb increased significantly against the background of significant reduction of Fe and Ni. The maximum concentrations of trace elements have been found out after starvation during: 3 months - Mn; 7 months - Cu, Zn, Ca, Mg, Co, Sr, Cd and Pb; 12 months - Cd. The maximum total concentrations of trace elements were also noted after seven-month starvation. The higher level of the trace elements in the tissues induced increased concentrations of glycine, cysteine, methionine, histidine, arginine - amino acids with detoxicating properities. High trace elements metabolism was accompanied by a multiple increase of the concentrations of free amino acids. It was revealed that at all stages of starvation the total concentrations of free amino acids significantly increased reaching maximum after five months of starvation. This fact confirm our recommendations for the terms to obtain leech homogenates for practical use. The results of the research may be used for more effective application of bioelements and amino acids contained in the tissues of the medical leech in the production of pharmaceuticals, food biological, cosmetics, biological additives.