Related Experiment Videos
Lipid composition and metabolism in liver and brain of vitamin B12-deficient rat sucklings
Insights
Vitamin B12 deficiency in rat sucklings impairs growth and alters lipid metabolism, leading to reduced methylation and accumulation of odd-chain fatty acids in the liver and brain.
Area of Science:
- Biochemistry
- Nutritional Science
- Developmental Biology
Background:
- Vitamin B12 is essential for numerous metabolic processes, including DNA synthesis and methylation.
- Deficiency during development can have profound and lasting effects on growth and organ function.
- Understanding the specific biochemical consequences of vitamin B12 deficiency is crucial for identifying potential interventions.
Purpose of the Study:
- To investigate the biochemical and physiological effects of vitamin B12 deficiency in developing rat sucklings.
- To assess the impact of deficiency on body weight, organ weights, and tissue vitamin B12 concentrations.
- To examine alterations in lipid metabolism, phospholipid methylation, and fatty acid composition in vitamin B12-deficient rats.
Main Methods:
- Comparison of 18-day-old rat sucklings from vitamin B12-deprived dams versus vitamin B12-supplemented dams.
- Measurement of body weight, liver weight, brain weight, and tissue vitamin B12 concentrations.
- Analysis of liver and brain lipid concentrations, phospholipid composition, and fatty acid profiles.
- Assessment of phospholipid methylation using [14C]ethanolamine and fatty acid/cholesterol biosynthesis from 3H2O and [14C]propionate.
Main Results:
- Vitamin B12-deficient rat sucklings exhibited lower body weight, liver weight, and brain weight.
- Liver and cerebellum showed a tenfold decrease in vitamin B12 concentrations.
- Liver lipid concentration was significantly increased, primarily due to triacylglycerol accumulation.
- Reduced methylation of ethanolamine phosphoglyceride to choline phosphoglyceride was observed in both liver and brain.
- Accumulation of odd-chain fatty acids (pentadecanoate, heptadecanoate) in liver and brain.
Conclusions:
- Vitamin B12 deficiency during early development severely impacts growth and causes significant alterations in lipid metabolism.
- Impaired phospholipid methylation and accumulation of odd-chain fatty acids are key biochemical consequences of vitamin B12 deficiency in developing rats.
- These findings highlight the critical role of vitamin B12 in normal development and metabolic homeostasis.
Abstract:
1. Rat sucklings (18-d-old) bred from vitamin B12-deprived dams were compared with vitamin B12-supplemented dams' offspring, which were considered normal rat sucklings. 2. The vitamin B12-deficient rat sucklings had lower body-weight, liver weight and brain weight. 3. Vitamin B12 deficiency was also evident from the tenfold lower concentrations of vitamin B12 in liver and cerebellum. 4. The concentration of liver lipid was markedly increased in vitamin B12-deficient rats; triacylglycerol accounted for most of the increase. In brain the lipid concentration was slightly decreased (less than 0.05). 5. The methylation of ethanolamine phosphoglyceride to choline phosphoglyceride was reduced in both liver and brain in vitamin B12-deficient rats, as measured after the administration of [14C]ethanolamine. A slight decrease in choline phosphoglyceride concentration could be a consequence of this finding. The composition of phospholipids was otherwise normal. 6. Odd-chain fatty acids (pentadecanoate and heptadecanoate) accumulated in both liver and brain of the vitamin B12-deficient rat sucklings and constituted approximately 1% of total fatty acid. 7. The biosynthesis of fatty acid and cholesterol from intraperitoneally-injected 3H2O and [14C]propionate was unchanged in vitamin B12 deficiency.