Vitamin B₁₂ Deprivation in the Rat: Effects on Folate Metabolism with Emphasis on the Nervous System

Abstract

Rats were subjected to deprivation of vitamin B₁₂ in order to induce neuropathy and to study effects on folate metabolism. Plasma vitamin B₁₂concentrations were maintained at about 100 pg/ml for 5 months. Neurological testing failed to reveal signs of neuropathy. Vitamin B₁₂ deprivation induced high plasma folate levels but had no effects on the levels of total folate in the liver or the nervous system, probably because of an adequate methionine supply. If the rats were starved, a smaller proportion of 5-methyltetrahydrofolate was found both in liver and brain of the vitamin-B₁₂-deprived animals. The folate concentration in the cerebrospinal fluid was lower than in the plasma but the values were correlated. There was a striking similarity between the liver and the brain in the way of handling ³H-folic acid and ¹⁴C-methyltetrahydrofolic acid. However, both substances showed a higher specific activity in the brain than in the liver, indicating a more dynamic state of brain folate.

Rest energy expenditure is decreased during the acute as compared to the recovery phase of sepsis in newborns

“…We considered the measurement of C-reactive protein (CRP) higher than 5 mg/liter as suggestive of infection [12]. Other laboratory tests such as cerebrospinal fluid changes suggesting bacterial meningitis [13], chest X-rays with the image of bronchopneumonia were also considered auxiliary criteria for the diagnosis of bacterial sepsis.…”