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Folate deficiency impairs brain oxygen delivery in rat
Author(s) -
Troen Aron Milton,
Hallacoglu Bertan,
Sassaroli Angelo,
Rosenberg Irwin H,
Fantini Sergio
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.lb392
Subject(s) - cerebral blood flow , hemoglobin , medicine , endocrinology , hemodynamics , hypoxia (environmental) , cognitive decline , neurodegeneration , oxygen saturation , oxygen , anesthesia , chemistry , dementia , disease , organic chemistry
Dietary vascular risk factors, including poor folate status are potentially modifiable predictors of cognitive impairment among older adults. In mouse, we have shown consuming a diet deficient in vitamins folate, B12 and B6 to cause a 30% decrease in brain capillary density in association with significant cognitive impairment. Similarly, folate deficiency in rat impairs cognition and causes cerebral microvascular damage, without concomitant neurodegeneration. We hypothesized that folate deficiency might result in functional decrements in cerebral oxygen delivery and vascular reactivity. We fed rats folate deficient diets for up to 20 weeks and used non‐invasive near‐infrared spectroscopy to measure absolute brain concentrations of oxygen free and bound hemoglobin, tissue oxygen saturation, and related hemodynamic parameters at rest and during transient mild hypoxia and hypercapnia. Brain hemoglobin concentration and oxygen saturation were significantly lower in folate deficient than in control rats (73±10 vs. 95±14 μM and 55%±7% vs. 66% ±4% respectively). In contrast, arterial oxygen saturation did not differ by diet with baseline values of 96%±2% for both groups, indicating that the decrements in brain were independent of blood oxygen carrying capacity. Our results implicate microvascular rarefaction and diminished oxygen delivery as a mechanism of cognitive impairment in folate deficiency.