M. S. Campos

Digestive utilization of goat and cow milk fat in malabsorption syndrome.

We studied the effects of goat and cow milk fat on the digestive utilization of this nutrient and on some of the biochemical parameters that are related to the metabolisim of lipids, using rats with a resection of 50% of the distal small intestine and control animals (transected). The fat content in all the diets was 10% but the lipid quality was varied: the standard diet was based on olive oil, while the other two diets included fat obtained from lyophilized goat milk and cow milk, respectively. The digestive utilization of the fat was lower in the resected animals than in the transected ones for all three diets studied. In both resected and transected animals. the apparent digestibility coefficient (ADC) of the fat was greater with the standard diet (olive oil) than with diets whose fat content was provided by goat or cow milk. The digestive utilization of the fat was greater in the transected and resected rats receiving a diet of goats milk (rich in medium-chain triglycerides) than those given a cow-milk-based diet and more closely approached the values obtained for olive oil. The consumption of goat milk reduced levels of cholesterol while levels of triglycerides, HDL, GOT and GPT remained with in the normal ranges, for both transected and resected animals. The advantageous effect of goat milk on the metabolisim of lipids with respect to cow milk suggests that the former should be included in the diet in eases of malabsorption snydrome.

Effect of iron deficiency on the digestive utilization of iron, phosphorus, calcium and magnesium in rats

The influence of the source of dietary Fe (ferric citrate alone or mixed with bovine blood at a proportion of 1:1 (v/v)) on the digestive utilization of Fe, P, Ca and Mg, and on haemoglobin regeneration efficiency (HRE) was investigated in control and Fe-deficient rats. Diet A contained (by analysis) 43.5 mg Fe/kg diet (as ferric citrate), and diet B contained 44.3 mg Fe/kg diet (ferric citrate-bovine blood). In Fe-deficient rats fed on diet A or B the apparent digestibility coefficient (ADC) of Fe increased by 42.3 and 45.7% respectively. The ADC of Ca and Mg decreased significantly in Fe-deficient rats regardless of the source of dietary Fe. The HRE increased by 72.9% in Fe-deficient rats fed on diet A, and by 91.1% in Fe-deficient animals fed on diet B. In Fe-deficient rats fed on Fe for 10 d the values of haematological variables approached normality. However, serum Fe remained low, indicating that Fe reserves were still depleted. A deficient dietary supply of Fe for 30 d did not significantly modify the numbers of circulating leucocytes.

Influence of cow or goat milk consumption on antioxidant defence and lipid peroxidation during chronic iron repletion

Despite Fe deficiency and overload having been widely studied, no studies are available about the influence of milk consumption on antioxidant defence and lipid peroxidation during the course of these highly prevalent cases. The objective of the present study was to assess the influence of cow or goat milk-based diets, either with normal or Fe-overload, on antioxidant defence and lipid peroxidation in the liver, brain and erythrocytes of control and anaemic rats after chronic Fe repletion. Weanling male rats were randomly divided into two groups: a control group receiving a normal-Fe diet (45 mg/kg) and an anaemic group receiving a low-Fe diet (5 mg/kg) for 40 d. Control and anaemic rats were fed goat or cow milk-based diets, either with normal Fe or Fe-overload (450 mg/kg), for 30 or 50 d. Fe-deficiency anaemia did not have any effect on antioxidant enzymes or lipid peroxidation in the organs studied. During chronic Fe repletion, superoxide dismutase (SOD) activity was higher in the group of animals fed the cow milk diet compared with the group consuming goat milk. The slight modification of catalase and glutathione peroxidise activities in animals fed the cow milk-based diet reveals that these enzymes are unable to neutralise and scavenge the high generation of free radicals produced. The animals fed the cow milk diet showed higher rates of lipid peroxidation compared with those receiving the goat milk diet, which directly correlated with the increase in SOD activity. It was concluded that goat milk has positive effects on antioxidant defence, even in a situation of Fe overload, limiting lipid peroxidation.

Effect of dietary inclusion of goat milk on the bioavailability of zinc and selenium in rats

The effects of dietary inclusion of freeze-dried goat and cow milk on the utilization of zinc and selenium, and on the metabolic fate of zinc, were studied in transected (control) and resected rats (resection of 50% of the distal small intestine). Intestinal resection reduced the apparent digestibility coefficient and zinc retention in the cow milk diet, whereas these biological indices were similar in transected (control) and resected rats with standard (without milk) and goat milk diets. The apparent digestibility coefficient and retention of selenium were not affected by intestinal resection in the animals fed with the three diets studied. In transected (control) and resected rats, the apparent digestibility coefficient and retention of zinc and selenium were higher for the goat milk diet than for the other two diets. Zinc deposits in the organs, expressed as microg/g dry weight were in order of decreasing concentrations: femur, testes, sternum, liver, kidney, heart, spleen, longissimus dorsi muscle and brain. Deposits were greatest with the goat milk diet, followed by the standard diet and were lowest for the rats given the cow milk diet, both for transected (control) and resected animals. We conclude that consumption of the goat milk diet produces a greater bioavailability of zinc and selenium and a greater deposit of zinc in key organs, for both the transected (control) and the resected rats, with respect to the standard diet and the cow milk diet.

Influence of nutritional iron deficiency anemia on DNA stability and lipid peroxidation in rats

OBJECTIVE Oxidative stress results from an imbalance between the formation and neutralization of pro-oxidants. Disturbance of the pro-oxidant/antioxidant balance is also considered to be a causative factor underlying oxidative damage to cellular molecules, such as DNA, causing strand breaks. There is considerable controversy about the antioxidant status in iron-deficiency anemia (IDA), but scant information is available regarding DNA integrity. In the present study, we investigated the relation between DNA stability and hepatic antioxidant capacity in rats with induced IDA. METHODS Peripheral DNA damage was assessed using an alkaline comet assay. Further, the hepatic antioxidant enzyme glutathione peroxidase and the production of thiobarbituric acid-reactive substances were measured in control rats and in those with induced IDA. RESULTS Comparison of the control and anemic rats showed no differences in thiobarbituric acid-reactive substances production in the cytosolic fraction of hepatic cells. Nor were there any differences in liver glutathione peroxidase enzyme activity or DNA stability, as demonstrated by the percentage of DNA in the head (90.77 in control rats versus 88.23 in anemic rats), tail (9.23 in control rats versus 11.76 in anemic rats), and olive tail moment (0.155 in control rats versus 0.141 in anemic rats). CONCLUSION IDA does not affect DNA stability or lipid peroxidation in rats, suggesting that there is enough compensatory capacity to keep antioxidant defenses high.

Influence of goat and cow milk on the digestive and metabolic utilization of calcium and iron.

The effects of goat and cow milk on the digestive and metabolic utilization of calcium and iron were studied in rats using a standard (non-milk) control diet. The digestive utilization of calcium is greater when the animals consume the goat-milk-based diet rather than that based on cow milk or the standard diet. The digestive utilization of iron, however, is similar for the goat-milk diet and the standard diet, and in both cases superior to that based on cow milk. The calcium content in the femur, sternum and Longissimus dorsi muscle (L.D. muscle) provides an indication of what happens during the utilization of the mineral; more is deposited when the rats consume a milk-based diet, particularly one based on goat milk. The iron content in the reserve organs, namely the liver and the spleen, is greater with the standard diet and the goat milk diet than with that containing cow milk. There is an obviously beneficial effect of goat milk on the metabolism of calcium and iron, which minimizes any interaction between the two minerals.ResumenSe ha estudiado el efecto de la leche de cabra y vaca sobre la utilización digestiva y metabólica de calcio y hierro en ratas, usando como dieta control una dieta estándar (sin leche). La utilización digestiva de calcio es superior cuando los animales ingieren la dieta elaborada con leche de cabra respecto a la dieta a base de leche de vaca y la dieta estándar; mientras que la utilización digestiva de hierro es del mismo orden para las dietas elaboradas a base de leche de cabra y dieta estándar y ambas superiores a la dieta a base de leche de vaca. El contenido de calcio en fémur, esternón y músculo Longissimus dorsi (músculo L.D.) refleja lo que ocurre en la utilización de este mineral; el depósito es mayor cuando las ratas ingieren dietas elaboradas con leche, especialmente con leche de cabra. El contenido de hierro en los órganos de reserva, hígado y bazo es superior con las dietas estándar y la elaborada con leche de cabra respecto a la dieta que contiene leche de vaca. Es evidente el efecto beneficioso de la leche de cabra en relación al metabolismo de calcio y hierro, minimizando las interacciones entre estos dos minerales.

Influence of nutritional iron deficiency development on some aspects of iron, copper and zinc metabolism

This paper examines the development of iron (Fe) deficiency and its possible interactions with trace elements such as zinc (Zn) and copper (Cu) by investigating iron-deficient and control rats. The effects of iron deficiency were studied at day 0, 10, 20, 30 and 40 in rats fed on an iron-free diet (diet ID). It was found that the critical period in the development of nutritional iron deficiency occurs after 30 to 40 days without iron supplementation. At this time the organism is unable to maintain haemoglobin levels without endangering the iron-dependent enzymatic groups which are essential for life. It was also demonstrated that in a situation of iron deficiency, there occurs a greater absorption of copper, while that of zinc remains unchanged. As iron deficiency progresses, the levels of copper in the spleen and the sternum increase. It is apparent that iron deficiency provokes more marked alterations in the metabolism of copper than of zinc.

Bioavaliability of Fe, Ca, P and Mg in Fe-deficient rats treated with different sources of dietary iron

Abstract Iron deficiency (D0) markedly decreases the concentration of iron and calcium in the liver, femur and sternum. We investigated the effect of the source of dietary iron [ferric citrate alone (citrate diet), or combined with bovine blood at a proportion of 1:1 (citrate + heme diet), and ferric protein (protein-Fe diet)] on the nutritive utilization of Fe, Ca, P and Mg in anemic and healthy rats. All diets contained the same amount of Fe (40 mg/kg diet). In Fe-deficient rats (DT) fed citrate, citrate + heme or protein-Fe diet the apparent digestibility coefficient (ADC) of Fe were 39%, 37% and 94% greater than in the respective control groups (C); hemoglobin regeneration efficiencies (HRE) were respectively 47%, 51%, and 172% greater than in the control groups. The ADC of Ca was not affected by Fe deficiency, whereas the ADC of Mg decreased significantly, and that of P increased under our experimental conditions. In Fe-deficient rats fed Fe for 10 days (DT), the concentrations of hemoglobin approached normal values. However, serum Fe remained low, indicating that Fe reserves were still depleted. Hepatic and femoral Fe concentrations were also lower in all DT groups, whereas Fe concentrations in the sternum increased significantly, suggesting an increase in erythropoiesis. After supply of dietary Fe for 10 days in iron-deficient groups (DT), Ca and P concentrations increased in sternum, a site assumed to have higher requirements for these minerals. In the liver these values tended to normalize, whereas in the femur Ca and P stores remained depleted. Mg concentrations after the replenishment period generally approached normality in all three organs.

Role of the proximal colon in mineral absorption in rats with and without ferropenic anemia

Abstract We studied the effects of iron deficiency on the absorption of different dietary sources of iron in vivo (non-heme, heme, and equal parts of both forms), and investigated the interactions between iron and calcium, phosphorus, magnesium, copper and zinc in the proximal colon of control and iron-deficient rats. Three perfusion solutions containing a different source of iron were used: solution 1, ferric citrate; solution 2, hemoglobin; solution 3, equal parts of ferric citrate and hemoglobin. We also tested the same perfusion solutions with 2,4-dinitrophenol (2,4-DNP), an inhibitor of oxidative phosphorylation (solutions 1-I, 2-I and 3-I). In control rats we observed three mechanisms of iron absorption: passive for soluble iron salts, active receptor-mediated for inorganic Fe complexes, and active receptor-mediates for heme iron. In anemic rats iron absorption was greater than in controls, except after perfusion with solution 2 (containing hemoglobin). Absorption increased as a result of the passive mechanism. The active component was influenced by the depletion of heme receptors under severe iron deficiency. The absorption of calcium, phosphorus, magnesium, copper and zinc was greater in iron-deficient animals than in the control group. After perfusion with solution 2 or 3, calcium, copper and zinc absorption were lower than after solution 1. We conclude that ferropenic anemia leads to increased absorption by the proximal colon of all minerals studied. This increase is due mainly to the passive route of absorption.

Goat milk during iron repletion improves bone turnover impaired by severe iron deficiency

The effect of goat or cow milk-based diets, with either normal Fe content or an Fe overload, on bone turnover and the mineralization process was studied in control and anemic rats during chronic Fe repletion. One hundred eighty male Wistar rats were studied during a pre-experimental period of 40 d in which they were randomly divided into 2 groups, a control group receiving the AIN-93G diet with normal Fe content (45 mg/kg of diet) and the Fe-deficient group receiving the AIN-93G diet with low Fe content (5mg/kg of diet) for 40 d. After the pre-experimental period, the rats were fed for 10, 30, or 50 d with goat or cow milk-based diets with a normal Fe content (45 mg/kg of diet) or an Fe overload (450 mg/kg of diet). In anemic rats, goat milk with normal Fe content increased levels of the biomarker of bone formation N-terminal propeptides of type I procollagen and diminished parathyroid hormone levels after only 10 d of supplying this diet, indicating the beginning of restoration of the bone demineralization induced by the anemia, which was not observed with cow milk. After 30 d of supplying the milk-based diets with normal Fe content or an Fe overload, biomarkers of bone formation and bone resorption were not different between control and anemic rats, indicating that the bone demineralization induced by the Fe-deficiency anemia had recovered, although the process of stabilization of bone turnover began earlier in the animals fed goat milk. In addition, a higher Ca deposit was observed in femur, which positively affects bone mineralization, as well as an increase of Fe in sternum, which indicates that the hematopoietic process essentially recovered earlier on the goat milk diet compared with the cow milk diet.