[Normal values of carboxyhemoglobinemia and methemoglobinemia in a sample of conscripts]. / Valori normali di carbossiemoglobinemia e di metaemoglobinemia in un campione di militari di leva.

Carboxyhemoglobin (COHb) and methemoglobin (MetHb) values in blood were measured in a population of 296 asymptomatic conscripts who were not under medical treatment and had no occupational exposure. The mean COHb value was 3.25 (S.D. = 1.45%) in smokers and 1.34 (S.D. = 0.8) in non-smokers, with a wide variability in both subgroups, particularly among smokers. The COHb levels in moderate smokers were lower than in heavy smokers, but smoking just before the blood test greatly increased the COHb levels. Non-smoking country dwellers had lower COHb levels than non-smoking city dwellers, but the COHb levels of smokers were independent of residence and were only smoking-related. The sample MetHb level was 0.81 (S.D. = 0.37) and was influenced by country living and smoking. Levels were lowest in non-smoking country dwellers (0.66, S.D. = 0.38%) and increased with moderate smoking (0.71, S.D. = 0.40%). Heavy smoker levels were independent of residence. Smoking just before the blood test had no effect on the value.

Insulin receptors in children's erythrocytes. Study on aging cells.

Aim of this study was to evaluate the influence of the red cell aging process on insulin receptor binding. In erythrocytes from 8 children with high reticulocyte count and 9 healthy age-matched subjects we studied insulin receptor binding in correlation with pyruvate kinase (PK) activity and creatine levels. Moreover maximum 125I-insulin bound % and PK activity were tested in four red cell fractions of different age. Our data show a significant correlation between 125I-insulin bound and either PK activity or creatine levels. In vitro experiments on red cell fractions of different age (as tested by creatine levels) evidence a lower decay of PK activity than insulin bound (p less than 0.05). Our results indicate that creatine content is the best marker of red cell age for insulin receptor studies.