Effects of excess vitamin B6 intake on cerebral cortex neurons in rat: an ultrastructural study

• Published in: Folia histochemica et cytobiologica 2005, Vol.43 (3), p.143
• Main Authors: Demir, Ramazan, Acar, Goksemin, Tanriover, Gamze, Seval, Yasemin, Kayisli, Umit Ali, Agar, Aysel
• Format: Article
• Language: English
• Subjects: Animals; Astrocytes - drug effects; Astrocytes - pathology; Astrocytes - ultrastructure; Axons - drug effects; Axons - ultrastructure; Blood-Brain Barrier - drug effects; Blood-Brain Barrier - pathology; Blood-Brain Barrier - ultrastructure; Cell Nucleus - drug effects; Cell Nucleus - pathology; Cell Nucleus - ultrastructure; Cerebral Cortex - drug effects; Cerebral Cortex - pathology; Cerebral Cortex - ultrastructure; Dose-Response Relationship, Drug; Eating; Male; Mitochondria - drug effects; Mitochondria - pathology; Mitochondria - ultrastructure; Neurons - drug effects; Neurons - pathology; Neurons - ultrastructure; Rats; Vitamin B 6 - administration & dosage; Vitamin B 6 - toxicity
• ISSN: 0239-8508; 1897-5631

The aim of this study was to investigate whether excess of vitamin B6 leads to ultrastructural changes in cerebral cortex of forty-eight healthy albino rats which were included in the study. Saline solution was injected to to the control groups (CG-10, n = 12 for 10 days; CG-15, n = 12 for 15 days; CG-20, n=12 for 20 days). The three experimental groups (EG-10, n = 12; EG-15, n = 12; EG-20, n = 12) were treated with 5 mg/kg vitamin B6 daily for 10 days (EG-10), 15 days (EG-15) and 20 days (EG-20). Brain tissues were prepared by glutaraldehyde-osmium tetroxide double fixation for ultrastructural analysis. No significant changes were observed in the control groups. The ultrastructural analysis revealed that the numbers of damaged mitochondria, lipofuscin granules and vacuoles were significantly higher in all the experimental groups than in the control groups (p < 0.05). However, synaptic density was significantly decreased in the experimental groups as compared to the control groups (p < 0.05). The results suggest that the excess of vitamin B6 intake causes damage to the cerebral cortex due to cellular intoxication and decreased synaptic density. Thus, careful attention should be paid to the time and dose of vitamin B6 recommended for patients who are supplemented with this vitamin.