Influence of cell age and ketoaminic linkage on rapid glycosylation of hemoglobin in human red cells in vitro.

In vitro the rate of synthesis of the aldiminic linkage between Hb and glucose depends on glucose concentration, length of incubation and some other physiological factors. To understand better the regulation of this synthesis and to verify the role of cell age and of basal HbA1 levels on the rate of synthesis of pre-A1, we studied red cells from 7 normal controls and 7 diabetics, with high HbA1 levels. We found that the content of HbA1 (stable glycosylated hemoglobin) is able to negatively affect the rate of synthesis of new pre-A1, according to a curvilinear model. These results suggest that in vitro the glycosylation process is saturable, and that elevated values of HbA1 are able to slow the synthesis of pre-A1 in vitro.