Nadp+ biosynthesis by rats receiving a pellagragenic diet

Rats showing signs of pellagra-like disease associated with gelatin ingestion were injected with [14C}-nicotinic acid into the portal vein and the incorporation of the label into hepatic NAD+ and NADP+ was determined. The quantity of NADP+ synthesized within 1 h after [14C]-nicotine acid injection by the experimental group, supplemented or not with dietary niacin, was 75% lower than that synthesized by the control group fed a casein control diet (141nmol h-1 g-1). The NAD+ and NADP+ contents of the liverof the experimental animals were 245 and 93 *g/g liver, respectively, i. e., significantly lower than those for the controls (597 and 210 *g/g liver, respectively). Dietary supplementation with niacin increased the NAD+ content to 317 */g liver but had no statistical effect on NADP+ content (75 *g/g liver) or NADP+ synthesis (46.5 in the free niacin group vs 37.0 nmol h-1 g-1 in the niacin-supplemented group). Therefore, NAD+ content did not seem to limit NADP+ synthesis. These results that the lower availably of NADP+ is responsible, at least in part, for some metabolic derangements in pellagra-like disease, such as a decrease in the activity of NADP+-dependent enzymes observed in quail muscle

Fenilcetonúria clássica com manifestaçäo de dermatite pelagróide / Classic phenylketonuria with pellagra-like dermatitis manifestation

A fenilcetonúria clássica, erro inato do metabolismo transmitido de modo autossômico recessivo, caracteriza-se habitualmente por retardo mental, eczema, diluiçäo pigmentar, alteraçöes neurológicas e hiperfenilalaninemia. Apresenta-se um paciente fenilcetonúrico que mostra, além das manifestaçöes freqüentemente relatadas, episódios de dermatite pelagróide fotossensível acompanhada de deterioraçäo do comportamento, e que respondem a terapêutica com nicotinamida. A fotossensibilidade é atribuída a diluiçäo pigmentar secundária a produçäo deficiente de melanina e possivelmente a diminuiçäo da absorçäo intestinal do triptofano, que leva a níveis reduzidos de nicotinamida, ambas provocadas pela hiperfenilalaninemia. Para o dermatologista, é importante atentar para os distúrbios metabólicos ao se deparar com a associaçäo retardo mental-dermatite pelagróide