Whole-blood and plasma selenium (Se) concentrations, red blood cell and plasma glutathione peroxidase activities, and red blood cell glutathione concentrations were investigated in 49 healthy pregnant women. Mean whole-blood and red blood cell Se concentrations started to decline after the 16th week and plasma Se after the 26th week of pregnancy. The lowest values were noted just before delivery. Negative correlations were found between the gestational age and both whole-blood and plasma Se concentrations: (r = ––0.560 (p < 0.001) and r = ––0.553 (p < 0.001), respectively. Plasma and red blood cell glutathione peroxidase activities started to decrease after the 20th and 30th week of pregnancy, respectively, and before delivery were significantly lower (p < 0.001) than during the 10th week of pregnancy. The red blood cell glutathione concentration increased significantly just before delivery. These results seem to confirm the supposition that in pregnant women with low or even moderate blood Se concentrations the requirement for the element significantly increases.
The authors obtained tissue samples taken at autopsy from 46 healthy individuals killed in accidents and from 75 corpses of victims of various diseases to analyze selenium levels. The per-weight-unit basis of selenium levels (all expressed as ng/gm wet tissue) in tissues decreased in the following order: kidney (469) > liver > spleen > pancreas > heart > brain > lung > bone > skeletal muscle (51). The highest proportion of body selenium was found in skeletal muscles (27.5%); much less selenium was found in bones (16%) and blood (10%). In the tissues of cancer corpses, the selenium levels were much lower than levels in controls. The lowest selenium levels were found in the livers of alcoholics. Tissue selenium levels found in the study were significantly lower than levels reported in Japan, United States, Canada, and other countries. The low selenium levels in the tissues of Polish residents result from inadequate selenium levels in the soil. The authors used selenium levels in tissues to calculate the amount of selenium in humans in Poland (i.e., approximately 5.2 mg). This level was similar to levels found in New Zealand (i.e., 3.0-6.1 mg), but it was lower than the mean level found in Germany (i.e., 6.6 mg) and in the United States (i.e., 13.0-20.3 mg).
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