Biomedical subjects
Publications and source records attributed to E Piatti.
In human erythrocytes, in the absence of specific enzymes, G1,6P2 synthesis and degradation are carried out by phosphoglucomutase PGM2 isoenzymes. The results presented, obtained by using partially purified preparations of these enzyme forms, suggest that erythrocyte G1,6P2 may play a crucial role in the physiological interconversion of several important sugar monophosphates.
Phosphoglucomutase can bind both negative and positive ions so that it may change its net electric charge according to the buffer species of the medium. For this reason the knowledge of the pIs of the erythrocyte phosphoglucomutase isoenzymes is not sufficient to forecast their separability by procedures based on charge separations such as ion exchange chromatography. In this paper we indicate the condition to obtain a satisfactory separation of the main erythrocyte phosphoglucomutase isoenzymes by DEAE-cellulose column chromatography. The pI values of the isolated isoenzymes are also reported and compared to those measured by others on whole hemolysates.
The metabolic effect of a lactate or pyruvate load and methylene blue (Mb) on hexose monophosphate shunt (HMPS) and Embden-Meyerhof pathway (EMP) were investigated in intact erythrocytes in the presence of glucose. Pyruvate enhances glucose consumption and 14CO2 production, lactate reduces 14CO2 production but glucose consumption is unchanged. These effects are dependent on the lactate and pyruvate concentrations in the buffer. A pyruvate load does not results to influence the net production of pyruvate, which is conversely markedly increased by Mb. The lactate load raises slightly the total pyruvate level but its rate of production is unchanged, with respect to that of the control. A considerable effect on the intracellular to extracellular pyruvate ratio is observed in these different conditions, as well as modifications in the levels of inorganic phosphate (Pi).