Summary. The pOz at which haemoglobin is half-saturated with oxygen (p50) was determined at fixed pCO2 (45 mmHg) and without altering the resulting pH and the level of organic phosphates in heparinized whole blood samples from 26 diabetic patients and 24 normal subjects of both sexes. Diabetic blood p50 was higher (29.79 + 1.68 versus 28.26 _ 1.16 mmHg, p < 0.001) and with a higher 2,3-diphosphoglyceric acid/haemoglobin molar ratio (1.04 + 0.15 versus 0.86 + 0.10, p < 0.001). The pH at a pCO2 of 45 mmHg was the same in the two groups. The observed p50 values were compared with those obtained after normalization in respect to pH and the level of 2,3-diphosphoglyceric acid. We conclude that glycosylated haemoglobins, known to have an increased affinity for oxygen when purified and in diluted solutions, do not play a significant role in the oxygen affinity pattern of diabetics at the concentrations normally found in vivo.
The preparation and evaluation of ethylene glycol-stabilized haemolysates for use äs control material for the assay of glycated haemoglobins is described. These haemolysates were prepared from normal and diabetic blood samples by following the procedure normally used to purify human haemoglobin, with the addition of dialysis to remove glucose from the labile fractions, and dilution with ethylene glycol. All the haemoglobin fractions were converted into the carbon monoxide form to increase their stability and were stored under different conditions. During a lOmonth period of storage at -20 °C no significant change in the glycated haemoglobins level was observed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.