The article discusses the role of conjugated lactic acid/ lactate anion (LacH/Lac-) and dihydrogenphosphate anion/ hydrogenphosphate anion (H2PO4-/HPO42-) pairs in the formation of the buffer properties of tissue as a factor determining pH. The buffer properties of homogenates of the tissue of adenocarcinoma of the mammary gland and the adjacent tissue were quantitatively characterized by the buffer capacity which was determined by potentiometric titration. The concentrations of acid anions were determined spectrophotometrically. The material was biopsy specimens of mammary gland adenocarcinoma (T1-4, N0-1, M0) and adjacent tissue of 22 patients aged from 33 to 75 years. It was found that the buffer capacity of tumors is in 2.5 times higher than in normal tissue. It was established that for the tumor tissue, the buffer capacity of the LacH/Lac- system is in 3 times higher, and the buffer capacity of the H2PO4-/HPO42-system is in 2.5 times greater than for normal untransformed tissue. Concentrations of lactate anions (1,93 ± 0,50 vs 0,57 ± 0,22; p <0.001) and phosphate anions (2,54 ± 0,39 vs 0,70 ± 0,19; p <0,001) in homogenates of the tumor tissue were significantly higher in tumor tissue in comparison with the adjacent tissue. A strong correlation was found between the concentration of phosphate anions and the buffer capacity for tumor tissue (r = 0,857; p = 0,002) and for adjacent tissue (r = 0,917; p <0,001). The correlation between the concentration of lactate anions and the buffer capacity for tumor tissues can be estimated as average (r = 0,626; p = 0,053), while it is absent for the adjacent tissue (r = 0,494; p = 0,147). The results suggest that the acid-base properties of homogenates of mammary adenocarcinoma tissues are determined by two buffer systems: LacH/Lac- and H2PO4-/HPO42-, while the intracellular acid-base homeostasis of non-transformed tissues is mainly determined by the H2PO4-/HPO42- system.
Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials
