effect of oral ascorbic acid pretreatment on feeding changes following injection in nucleus accumbens shell in adult male rats

ABSTRACT

Ascorbic acid [AA] is not synthesized in the brain but it is actively transported through blood-brain barrier by SVCT2 cotransporter and it is stored in high concentrations with heterogeneous distribution in areas such as nucleus accumbens shell [AcbSh] in the mammalian brain. Previous studies have shown that Ascorbic acid injection into AcbSh decreases feeding; therefore, in the present study we evaluated the effects of oral Ascorbic acid pretreatment on changes in feeding upon its injection in AcbSh in adult male rats. Sixty-three adult male rats [220-280 g] were divided into five treatment and five pretreatment groups. The treatment groups included the control [intact] group, sham-operated Ascorbic acid group that received normal saline as vehicle, and three other groups that received different doses of ascorbic acid [10, 50 and 250 microg/rat] by injection into AcbSh for four days. The pretreatment groups received Ascorbic acid [100 mg/kg] for 15 days via gastric gavage before receiving the aforementioned doses in treatment groups into intra nucleus AcbSh. Feeding measurement was repeated every 12 hours by automatic metabolic cage. The results indicated that all injected doses of Ascorbic acid [10, 50 and 250 microg/rat] into nucleus accumbens shell decrease food intake [P<0.05] in rats and oral Ascorbic acid pretreatment had no effects in this regard. Our findings show that ascorbic acid is an effective factor in feeding regulation. Oral pretreatment seems to have no influence on the central effects of ascorbic acid in the nucleus accumbens shell