Riboflavin deficiency, metabolic rate and brown adipose tissue function in sucking and weanling rats

Abstract

1. The effects of riboflavin deficiency on growth, whole-body oxygen consumption, cytochrome c oxidase (EC 1.9.3.1) activity and GDP-binding capacity of brown adipose tissue were measured in three groups of rats: sucking pups, weanling rats, and dams. Control groups were weight-matched, pair-fed or fed ad lib.2. Riboflavin deficiency reduced growth rate and increased the activation coefficient of erythrocyte glutathione reductase (NAD(P)H) (EC 1.6.4.2), as predicted. In sucking pups it also reduced whole-body O2 consumption per unit body-weight, especially after noradrenaline stimulation. In weanling rats, however, it increased O2 consumption both before and after noradrenaline stimulation.3. Cytochrome c oxidase (EC 1.9.9.1) activity of brown adipose tissue was not consistently affected by riboflavin deficiency. Binding of [3H]GDP to the mitochondria was increased in the deficient weanling rats.4. Weanling rats therefore, seemed better able to withstand the effects of severe depletion. Their reduced growth and increased non-shivering thermogenesis helped to counteract the unfavourable ratio of riboflavin: other tissuebuilding materials. The relevance for thermoregulation in riboflavin-deficient children is discussed.

Severe riboflavin deficiency induces alterations in the hepatic proteome of starter Pekin ducks

“…Our proteomic analysis revealed that fatty acid β-oxidation, TCA cycle and oxidative phosphorylation processes were probably impaired in RD ducks, which may lead to insufficient ATP production and subsequent growth retardation. This result might explain reduced energy utilisation for growth owing to RD indicated by markedly reduced weight gain per unit of feed consumed in this study, which is also observed in previous studies in rats (12)(13)(14)(15)41,81) and pigs (43) . The results support the hypothesis that the lower food utilisation efficiency as the consequence of RD is due to incomplete oxidation of nutrients (80,82,83) .…”

“…This finding is consistent with the hypothesis that flavoprotein expression may be down-regulated owing to reduced supply of riboflavin in the diet and is in line with a human study (42) . Previous studies proved that RD markedly decreased feed intake in rats (11)(12)(13)(14)(15)41) , pigs (43) and ducks (17)(18)(19) . As expected, an CPF, pair-fed with the CAL to the mean daily intake of the RD group; CAL, ad libitum control diet.…”

“…Previous studies described that RD could depress growth (11)(12)(13)(14)(15)(17)(18)(19)41) and induce fatty livers (21,22) of animals. In the present study, growth depression, liver enlargement and liver lipid accumulation were observed in RD ducks, accompanied by a high mortality rate.…”

“…Owing to its involvement in primary metabolic pathways, riboflavin deficiency (RD) causes impaired growth, glossitis, anaemia and dermatitis in humans (8)(9)(10) . Also in animal studies, RD depresses growth and even results in death of rats (11)(12)(13)(14)(15) , fish (16) and ducks (17)(18)(19) . Disturbed lipid handling was shown to be a major consequence of RD in both humans and animals.…”

Efectos de la deficiencia de riboflavina sobre el desarrollo del tejido dentoalveolar, en ratas*

“…Los resultados del promedio de peso corporal obtenido en las ratas del presente trabajo concuerda con los obtenidos por Patterson y Bates (17) , quienes encontraron que los pesos de las ratas con deficiencia de vitamina B 2 mantienen diferencias significativas menores al compararse con el grupo control que contiene dieta de vitamina B 2 en proporciones adecuadas a sus requerimientos.…”