It has been suggested that the lateralization of the human brain underlies hemispheric specialization and that it can be observed also on a biochemical level. Biochemical laterality appears to be a basis of volumetric or functional asymmetry but direct relationships among them are still unclear. Moreover, age-related differences between the right and left hemispheres are not well documented in various rat strains. In the current study, biochemical markers sensitive to Alzheimer disease (activities of high-affinity choline uptake and of nitric oxide synthases, expression of 17beta-hydroxysteroid dehydrogenase type 10) were estimated in both hemispheres of young and old male Wistar/Long Evans rats. Our experiments indicate (1) differences in some biochemical markers between young Wistar and Long Evans rats (the activities of endothelial nitric oxide synthase are higher in Long Evans and those of citrate synthase in Wistar rats), (2) more similar brain asymmetry of healthy human/young Wistar brains when compared to those of young Long Evans, (3) the decrease in asymmetry of the physiologically left/right lateralized biomarker during aging (the activity of the high-affinity choline uptake decreases more markedly in the left side of old Wistar rats) in accordance with the HAROLD model, (4) the age-related shift to reversed left/right asymmetry of the physiologically right/left lateralized biomarker (the activity of inducible nitric oxide synthase increases especially in the left side of old Long Evans rats), and finally (5) age-related differences in physiologically unlateralized biomarkers between Wistar and Long Evans rats (changes in the activities of neural/endothelial nitric oxide synthases or in expression of 17beta-hydroxysteroid dehydrogenase type 10 are more asymmetrical in old Wistar when compared to rather bilateral alterations of old Long Evans animals). It seems that the physiological lateralization of the human or rat brains on a biochemical level and their age-related alterations are dependent on biomarker type/function. By our opinion, it is difficult, perhaps impossible, to make one simple universal model, at least on a biochemical level. Since lateral analyses are of sufficient sensitivity to reveal subtle links, we recommend using Wistar rather than Long Evans rats in modeling of diseases accompanied by alterations in brain asymmetry.

• MeSH
• 17-Hydroxysteroid Dehydrogenases metabolism   MeSH
• Alzheimer Disease metabolism   MeSH
• Biomarkers metabolism   MeSH
• Choline metabolism   MeSH
• Citrate (si)-Synthase metabolism   MeSH
• Species Specificity MeSH
• Functional Laterality MeSH
• Rats MeSH
• Humans MeSH
• Brain metabolism   MeSH
• Rats, Long-Evans MeSH
• Rats, Wistar MeSH
• Aging metabolism   MeSH
• Nitric Oxide Synthase Type I metabolism   MeSH
• Nitric Oxide Synthase Type II metabolism   MeSH
• Nitric Oxide Synthase Type III metabolism   MeSH
• Cerebrum metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Humans MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• 17-Hydroxysteroid Dehydrogenases MeSH
• Biomarkers MeSH
• Choline MeSH
• Citrate (si)-Synthase MeSH
• Nitric Oxide Synthase Type I MeSH
• Nitric Oxide Synthase Type II MeSH
• Nitric Oxide Synthase Type III MeSH