SEARCH FOR STIMULAS AFFECTING THE LEVEL OF INORGANIC POLYPHOSPHATES IN THYMOCYTES Ergasheva Diyora Сenter of advanced technologies under the Ministry of Innovative Development of the Republic of Uzbekistan, e-mail: info@cat-science.uz
Phosphorus is a vital element of all living organisms, being part of the most
important organic compounds, including nucleic acids, ATP and other nucleoside
phosphates, phospholipids, phosphorylated proteins, and carbohydrates. An insufficient
amount of this element in the environment is an unfavorable factor limiting growth and
development, and its absence leads to the death of organisms. Inorganic polyphosphates
(Poly-P) is the oldest molecule found in all living organisms from bacteria to mammals,
they are multifunctional molecules depending on the subcellular location in different
types of organism.
In this regard, an important strategy for survival in changing environmental
conditions for organisms is the accumulation of reserves of phosphorus compounds.
These compounds are varied. These can be organic phosphorus compounds, such as
phytin (Ca-Mg-salt of inositol phosphate) of higher plants, phosphomannan of some
yeast species (
Hansenula capsulata ), teichoic acids of the bacterial cell wall.
To date, it is known that Poly-P in mammalian cells play a predominantly regulatory
role. Although the specific enzymes involved in the synthesis of Poly-P are still
unknown. However, from the literature and the results of our studies, it is known that
the synthesis of Poly-P is associated with the energy metabolism of the cell, as well as
the integrity of the membrane. To date, the issue of studying the pathways of Poly-P
metabolism in mammalian cells remains relevant.
The aim of this work was to assess the phosphate-accumulating potential of rat
thymocytes, as well as to study the features of the metabolism of inorganic polyP in
these cells, which accumulate Pi most efficiently.
To achieve this goal, thymocytes of outbred rats weighing 100-120 grams were
isolated using differential centrifugation. The isolated thymocyte suspension was
incubated with a 20 µM DAPI probe at room temperature for 40 minutes. During
incubation, thymocytes were pipetted every 5-7 minutes.
Fluorescence was performed using an Agilent Technologies fluorometer (Cary
Eclipse Fluorescence Spectrophotometer). All recordings were made in 3 ml glass
cuvettes with Ringer's solution without glucose (medium composition: 5 mM KCl, 135
mM NaCl, 11 mM HEPES, 2 mM CaCl, 1 mM MgCl, pH 7.3).
To study the features of Poly-P metabolism in thymocytes, a modified measurement
of Poly-P fluorescence using DAPI was used. Changes in the level of Poly-P on the
main molecule of energy metabolism, glucose, were taken as a control. Application of
10 mM glucose to incubated thymocytes in a glucose-free medium caused an increase in
DAPI-polyP fluorescence in thymocytes. In the incubation medium without the addition
of glucose, a decrease in DAPI-polyP fluorescence was observed, which indicates that
the metabolism of Poly-P is inextricably linked with the energy metabolism of the cell.
The results obtained can be used to further study the effect of activators and
inhibitors of polyP metabolism in thymus cells.