Celio Kenji Miyasaka

Dietary polydextrose increases calcium absorption in normal rats

BACKGROUND: Gastric surgery is known to cause bone disorders, possibly related to an impaired capacity for the absorption of dietary calcium. AIM: To verify if polydextrose (PDX) could stimulate calcium absorption in partially gastrectomized and sham operated rats. METHODS: The rats were laparotomized (sham-operated control) or partially gastrectomized (Billroth II), in groups of 20 each. Half in each operated group were fed a control diet (AIN-93M) without PDX or the same diet containing (PDX 50g/Kg of diet) for eight weeks. The rats were divided into four subgroups: sham-operated and gastrectomized without PDX; sham-operated and gastrectomized with PDX. On the final day of the study, total blood was collected for determination of serum calcium concentration. RESULTS: In the diet with PDX, excretion of calcium in the feces was significantly lower than in the groups not receiving PDX, irrespective of the operation. Apparent calcium absorption and serum calcium was higher in the sham operated PDX fed group than in the control group. In sham operated rats, the calcium concentration in bone was higher in the PDX fed group. CONCLUSION: The polydextrose feeding increased calcium absorption and bone calcium concentration in normal rats, which may be relevant for decreasing the risk of osteoporosis. Partially gastrectomy did not affect the bone calcium concentration in 56 days of experimental period.

Ingestion of polydextrose increase the iron absorption in rats submitted to partial gastrectomy

PURPOSE To investigate whether polydextrose stimulates iron absorption in rats submitted to partial gastrectomy and sham operated. METHODS The rats were submitted to partial gastrectomy (Billroth II) or laparotomy (sham-operated control), in groups of 20 and 20 each respectively. The animals were fed with a control diet (AIN-93M) without polydextrose or a diet containing polydextrose (50g/Kg of diet) for eight weeks. They were divided into four subgroups: sham-operated and Billroth II gastrectomy and with or without polydextrose. Two animals died during the experiment. All rats submitted to gastrectomy received B-12 vitamin (intramuscular) each two weeks. The hematocrit and hemoglobin concentration were measured at the start and on day 30 and 56 after the beginning of the experimental period. At the end of the study, the blood was collected for determination of serum iron concentration. RESULTS The diet with polydextrose reduced the excretion of iron. Apparent iron absorption was higher in the polydextrose fed groups than in the control group. The haematocrit and haemoglobin concentration were lower after Billroth II gastrectomy rats fed the control diet as compared to the polydextrose diet groups. CONCLUSION Polydextrose increase iron absorption and prevents postgastrectomy anemia.

Partial gastrectomy associated to anterior truncal vagotomy: alterations in metabolism of the calcium. Experimental study in rats

RACIONAL: O calcio nao e absorvido na ausencia de acido cloridrico e a osteomalacia e osteoporose podem ocorrer; este fato e bem reconhecido em pacientes que se submeteram a gastrectomias. OBJETIVO: Avaliar os efeitos da gastrectomia parcial associada a vagotomia troncular anterior na absorcao e metabolismo de calcio. METODOS: Dezoito ratos Wistar machos e adultos foram submetidos a gastrectomia parcial e vagotomia troncular anterior (oito animais) e a laparotomia simples como grupo controle (10 animais). O consumo de dieta e o peso dos animais foram monitorados tres vezes por semana. Os animais receberam dieta oral formulada experimentalmente (AIN-93M), durante 8 semanas. O calcio serico, calcio urinario e fecal, absorcao aparente de calcio, atividade da enzima fosfatase alcalina e calcio osseo foram mensurados apos 60 dias de observacao. RESULTADOS: Os animais controle apresentaram medias estatisticas maiores (P<0.05) para o consumo de dieta, ganho de peso, calcio serico, calcio urinario, excrecao de calcio nas fezes, absorcao aparente de calcio e atividade da enzima fosfatase alcalina comparados aos animais do grupo gastrectomizado. Entretanto, a concentracao de calcio osseo foi superior no grupo de animais gastrectomizados (P<0,05) quando comparado com o grupo controle. CONCLUSAO: A gastrectomia parcial associada a vagotomia troncular anterior mostrou ser um bom modelo experimental para estudo com o metabolismo de calcio, ocasionando diminuicao da absorcao de calcio, calcio serico, calcio urinario e fosfatase alcalina. No entanto, para alteracoes a nivel osseo em ratos, sugere-se um estudo experimental em periodo maior.

Influência da dieta com galactooligossacarídeos sobre a absorção de cálcio em ratos normais e gastrectomizados

OBJECTIVE To determine whether the galactooligosaccharide stimulates calcium absorption in partially gastrectomized rats. METHODS Animals were submitted to laparotomy (sham-operated control) and partial gastrectomy (Billroth II) in groups of 20. They were fed a control diet (AIN-93M) without galacto-oligosaccharide or a diet containing (galacto-oligosaccharide - 50 g/kg diet) for eight weeks. The animals were divided into four groups: sham-operated and non-gastrectomized with galactooligosaccharide, sham-operated and gastrectomized without galactooligosaccharide. On the final day of the study, whole blood was collected for determination of serum calcium concentration. RESULTS In the group with galactooligosaccharides calcium excretion in feces was significantly lower than the group without prebiotics. The apparent absorption of calcium in gastrectomized and normal rats was higher in groups fed with galactooligosaccharide than in the control diet group. CONCLUSION The ingestion of galactooligosaccharides prevents osteopenia in partially gastrectomized rats.

A ingestão de prébioticos previne a malabsorção de ferro e anemia induzidas pela gastrectomia?: Estudo experimental em ratos

BACKGROUND: The ingestion of two prebiotics, galactooligosaccharide (GOS) and polydextrose (PDX), leads to an increase in iron absorption and promotes recovery from anemia in gastrectomized rats. AIM: To study whether GOS + PDX stimulate iron absorption in gastrectomized and normals rats. METHODS: Rats were laparotomized (sham-operated control) and partially gastrectomized (Billroth II) in groups of 20 each. Animals from both treatments were subsequently fed a control diet (AIN-93M) or the same diet supplemented with GOS and PDX (25 g/Kg of diet each) for eight weeks. They were divided into four subgroups, i.e., sham-operated and gastrectomized without GOS + PDX, sham-operated and gastrectomized with GOS + PDX. Two rats died during the experiment. All gastrectomized rats received an intramuscular injection of vitamin B-12 every two weeks. Hematocrit (HCT) and hemoglobin concentration (HGB) were measured at the start and on day 30 and 56 days after the start of feeding. On the final day of the study, total blood was collected for determination of serum iron concentration. RESULTS: In the diet with GOS + PDX, iron excretion in feces was significantly lower than without the prebiotics. Apparent iron absorption and serum iron was higher in the GOS + PDX fed groups (both sham operated and gastrectomized) than in the non-GOS + PDX fed groups. The HCT and HGB concentrations were significantly lower in gastrectomized rats than in the control group, however, GOS + PDX feeding improved HGB levels in this group. CONCLUSION: The association of the GOS + PDX increase absorption of iron in sham-operated and gastrectomized rats and still prevent postgastrectomy anemia.

Effects of the partial gastrectomy associated to anterior truncal vagotomy in the metabolism of the iron in rats

PURPOSE To evaluate the effects of the partial gastrectomy associated to anterior truncal vagotomy in the absorption and metabolism of iron. METHODS Eighteen adults male Wistar rats were submitted to the partial gastrectomy associated to anterior truncal vagotomy (eight animals) and the sham operation (10 animals, control group). The diet consumption and the weight gains of the animals were monitored three times during the week. The animals received supplements of vitamin B12, for the prevention of the megaloblastic anemia, and a formulated experimental diet orally and denominated AIN-93M by 8 weeks. The fecal iron, apparent absorption of the iron, haematocrit, haemoglobin and serum iron were measured after 60 days. RESULTS The animals undergoing sham operation presented larger statistical averages (p<0.05) for the diet consumption, weight gains, apparent absorption of iron, haematocrit, haemoglobin and serum iron compared to the gastrectomized group. However, the excretion of iron in feces was larger in the gastrectomized group (+14.3%) (p<0.05) when compared to the control group. CONCLUSION Partial gastrectomy associated to anterior truncal vagotomy showed to be a good experimental model the study of iron metabolism, decreasing the haematocrit, the haemoglobin and the iron absorption, consequently causing anemia.