[Preliminary study on P50 and on other parameters correlated with hemoglobin function in normal subjects chosen at...

In a wide survey on normal non-selected healthy adults, the Authors have found normal pHs in venous blood, a P50 slightly shifted to the left, in comparison with the mean values reported in other series for males and females, normal Hb amounts, normal 2,3-DPG levels, normal met-hemoglobin values and increased rates of Hb-CO. All these data and the possible relationship among them are discussed, with particular reference towards P50 and Hb-CO, which appears to be mainly raised, even if not only, in smokers people. At this regard the Authors hypothetize that if the four hemes of hemoglobin are fully saturated with CO, a right shifted oxy-hemoglobin dissociation curve of variable extent will be observed, whereas, if the hemes are not fully saturated, the curve could be shifted, more or less, towards the left. These two conditions could be coexisting in an unstable, non-enzymatic equilibrium, which could modify by itself the usual sigmoid shape (and the P50 values) of the whole blood oxygen affinity.