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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Iron-deficient rats have an impaired work performance, even when their anemia is corrected by exchange transfusion. Muscle activity is associated with a higher blood lactate concentration than is observed in iron-replete animals. The accumulation of lactate is a result of excessive production as lactate clearance from the blood was shown to be unaffected. By adjusting the work load to a lower level, it was possible to divide iron-deficient animals into two groups, one capable of continued treadmill running and another in which animals stopped before 20 min. In the former, blood lactate concentration reached a plateau at moderate levels, whereas it continued to increase in the latter until the animal stopped running. Levels of alpha-glycerophosphate oxidase in skeletal muscle mitochondria were found to be much lower in the second group (P < 0.001). Lactate infusion into normal animals was shown to interfere with work performance, and maintenance of a normal pH in iron-deficient and iron-replete animals did not prevent the impairment in work associated with high blood lactate concentrations. Additional evidence was obtained that energy substrate (blood glucose and free fatty acids, muscle glycogen) was adequate in irondeficient animals. Oxygen tension in their vena caval blood was higher than in controls. Furthermore, the in situ behavior of electrically stimulated gastroenemius and soleus muscles appeared similar to that of control animals. Because the stimulation of the single muscle in the iron-deficient animal did not result in appreciable elevation of blood lactate and did not show impaired contractility further supported the hypothesis that the elevation of blood lactate caused the decreased work performance. It is concluded that iron deficiency by a depletion in the iron-containing mitochondrial enzyme, alpha-glycerophosphate oxidase, impairs glycolysis, resulting in excess lactate formation, which at high levels leads to cessation of physical activity.
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PMID:Lactic acidosis as a result of iron deficiency. 44 49

A brief survey of the literature on the side effects of oral contraceptives is given. Of the many influences on laboratory results those related to (reversible) cholestasis or to a change in protein synthesis are the most important ones. A decrease of the tolerance for glucose is sometimes observed. Few of the clinical side effects attributed to oral contraceptives can be directly correlated with the pharmaceutical action of these drugs. Many so-called side effects of the pill are due to other factors such as altered psychosociological or sexual behavior, etc. However, among users of oral contraceptives there is a significant decrease in the number of benign tumors, particularly of the breast, the uterus and the ovaries. It is still an open question if this also signifies protection against cancer. Anemias due to iron deficiency are less frequent among users of the pill. According to recent studies arterial hypertension and cholecystopathies are probably directly related to oral contraceptives, but a causal relation has not been proven for migraine, headaches, depression etc. An elevated risk for vascular complications seems to be well established: there is a 4-6-fold increase of the estimated risk for venous thrombo-embolism and a 4-9-fold increase for cerebrovascular accidents among users of oral contraceptives when compared with nonpregnant women of the same age not using the pill. Oral contraceptives act as a supplementary factor of risk which may cumulate with other similar factors, such as arterial hypertension, hyperlipidemia, overweight, smoking etc. Mortality due to oral contraceptives is very much 10-50 x) inferior to the one caused by delivery and the post partum state. Since the number of failures in prevention of pregnancies is less for oral contraceptives than for any other method of contraception, the overall risk of death under oral contraceptives in this age group of women is least.
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PMID:[Real and seeming side-effects of oral contraceptives with an emphasis on medical and haematological problems. Review of literature (author's transl)]. 79 Mar 74

Candida tropicalis IBFM 303 is capable of the active production and liberation of flavins during the oxidation of solid paraffins with the carbon chain consisting of 20 carbon atoms and more. Unlike other known strains, this strain does not accumulate considerable amounts of the vitamin neither on media containing liquid n-paraffins not on media with glucose, even under the conditions of iron deficiency.
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PMID:[Increased flavinogenesis in 1 of the strains of Candida tropicalis]. 120 13

Comparative studies of the process of possible overproduction of flavins by cultures with different flavinogenous activity grown on media with hydrocarbons and glucose have been carried out. The strains with a high flavinogenous activity, Candida guilliermondii and Torulopsis famata O-3, produced more flavins on media containing hydrocarbons than the cultures with a low flavinogenous activity. At a high content of iron in the medium, which is unfavourable for overproduction of riboflavin the rate of flavinogenesis is higher on hydrocarbons than on sugars, especially on alkanes with a longer chain in the strain O-3. Under the conditions of iron deficiency, the activity of flavinogenesis is higher on glucose in the case of both cultures. Iron deficiency in media containing hydrocarbons and their oxygenated derivative (cetyl alcohol, palmitic and acetic acids) has no such effect on the production of flavin by T. famata O-3 as in the glucose containing media. On media with ethanol, overproduction of the vitamin by the strain O-3 obeys the same relationships as on media with glucose. Possible factors that may have effect on the elevated synthesis are discussed.
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PMID:[Increased flavin synthesis in yeasts utilizing hydrocarbons]. 123 55

The interactive effect of iron deficiency and dietary carbohydrate type on growth and thyroid hormone status of Sprague-Dawley rats was studied. Rats were fed either an iron-adequate (approximately 35 micrograms Fe/g) or an iron-deficient (less than 3 micrograms Fe/g) diet that contained 70% carbohydrate. The carbohydrate sources were 100% cornstarch (STARCH), 85.7% cornstarch and 14.3% sucrose (STARCH/SUCR), 71.4% cornstarch, 14.3% sucrose and 14.3% dextrin (DEXTRIN), or 100% sucrose (SUCROSE). After 4 wk, iron-deficient rats weighed less than the iron-adequate rats and were severely anemic. Total food intake was lower in iron-deficient than in iron-adequate animals; it was also significantly lower in SUCROSE-fed animals relative to other carbohydrate groups. Plasma glucose concentrations were significantly higher in iron-deficient rats than in iron-adequate rats, but plasma thyroid hormones, thyroxine and triiodothyronine, and liver thyroxine monodeiodinase activity were lower. Deiodination of reverse triiodothyronine in liver was unaffected by iron deficiency regardless of carbohydrate treatment. The STARCH-fed animals had higher rates of hepatic thyroxine monodeiodinase activity than rats fed the other dietary carbohydrates. The two main conclusions from this study are that thyroid hormone metabolism is altered by iron deficiency regardless of food intake and that the best purified rodent diet for this type of study would contain a mixture of carbohydrate types to avoid the stimulation of thyroxine monodeiodinase by a 70% cornstarch diet.
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PMID:Type of dietary carbohydrate affects thyroid hormone deiodination in iron-deficient rats. 156 71

In order to determine effects of iron deficiency on the living body, rats were given the iron deficient diet (Group 1, iron content, 0.32mg/100g), the complete diet added with iron (Group 5, iron content, 32.5mg/100g), the diet added with 1% chlorella (Group 2, iron content, 2.2mg/100g), the diet added with 5% chlorella (Group 3, iron content, 7.4mg/100g), or the diet added with 10% chlorella (Group 4, iron content, 13.9mg/100g). For the first 30 days, rats of all groups were given the iron deficiency diet to make them iron deficient, and were subsequently given the respective diet during the next 30 days to observe various changes in the conditions of rats. Following results were obtained. 1) When rats were reared for 30 days with the iron deficient diet, rats of these groups became anemic and their hemoglobin concentrations and hematocrit values lowered. Rats of Groups 3, 4 and 5 fed with the diets containing certain amounts of iron rapidly recovered, while the recovery of those of Group 2 fed with less iron content diet was delayed. Group 1 fed with the iron deficient diet showed no recovery. 2) Examination of effects of these diets on the rats body weight gains revealed that the growth of Groups 1 and 2 with iron deficiency was delayed notably (p less than 0.01) as compared with Group 5 and that of Group 3 was likewise restrained (p less than 0.05). The relative organ weights of all rats were examined. The liver weight in Groups 1, 2, 3, 4 was lower than that in Group 5, while that of the spleen in Groups 1 and 2 was higher than that in Group 5. 3) The Numbers of erythrocyte decreased in Groups 1 and 2 (p less than 0.01) and increased in Groups 3 and 4 (p less than 0.01) as compared with Group 5. There was no direct relation between the iron content in the diet and the number of leukocytes and their compositions. 4) Serum iron decreased remarkably in Groups 1 and 2 (p less than 0.01) but there were no intergroup differences in blood glucose value. 5) When osmotic fragility of erythrocyte membranes was expressed in term of NaCl concentration to indicate 50% hemolysis, Groups 1, 2 and 3 apparently increased their resistance as compared with Group 5 (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of chlorella on rats with iron deficient anemia. 182 19

The impact of varying severities of iron-deficiency anemia on fasting blood glucose, plasma triiodothyronine, heart norepinephrine concentrations and resting oxygen consumption were evaluated. Male weanling Sprague-Dawley rats were assigned to one of six dietary groups (4, 6, 11, 16, 23 or 40 mg Fe/kg diet) for 6 wk. Hemoglobin, liver iron and transferrin saturation were significantly lower in the 4 and 6 mg Fe/kg diet groups relative to the other groups and were indicative of anemia, low tissue iron stores and impaired erythropoiesis. Fasting blood glucose and heart norepinephrine concentrations were significantly higher and lower, respectively, in the 4 and 6 mg Fe/kg diet groups than the three highest dietary Fe groups. Although fasting blood glucose was significantly inversely correlated (r = -0.89, P = 0.0001) with hemoglobin concentration; a significant quadratic relationship (R 2 = 0.70, P = 0.0001) existed between hemoglobin and heart norepinephrine concentration. Differences in plasma triiodothyronine concentrations and resting oxygen consumption were not significant among the groups. Thus, base on hemoglobin concentration as an index of the severity of iron deficiency, these findings demonstrate that certain physiological manifestations of iron deficiency occur at even moderate-to-mild degrees of anemia.
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PMID:The impact of varying degrees of iron nutriture on several functional consequences of iron deficiency in rats. 201 82

We succeeded in isolating biotypes of Pseudomonas fluorescens forming phenazine derivatives exclusively under conditions iron deficiency. A culture medium containing traces of beryllium with glucose as the only carbon source allowed these microorganisms to grow under production of a brilliant red colour. Without beryllium the colonies were brown in colour. Spectroscopic investigations showed the red pigment to be a mixture of di- and trihydroxyphenazine carboxylic acid. UV/VIS measurements of the culture medium indicated the additional presence of ironcomplexing proferro-rosamines.
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PMID:Isolation of Pseudomonas fluorescens producing phenazine derivatives exclusively under strains conditions of iron deficiency. 212 4

The longitudinal gradient of intestinal iron transfer was investigated in normal and iron-deficient male Sprague-Dawley rats in vitro and in vivo. In normal rats in vitro iron transfer in the duodenum was approximately 3 times higher than in the jejunum and decreased in the ileum to approximately half the jejunal values. Compared to the controls in vitro iron transfer was increased 3-4 times in the duodenum and in the first jejunal segment and 2-3 times in the second jejunal segment. No significant adaptation to iron deficiency was found in the rest of the small intestine. Iron transfer rates showed the same longitudinal pattern when iron was chelated with nitrilotriacetic acid (NTA) or with ascorbate. The absorbed iron quantities, however, were approximately 5 times lower when Fe-ascorbate was used, which might be due to differences in bioavailability. Omission of Fe-NTA and Fe-ascorbate had no impact on the vitality of the segments. Glucose transfer was used as vitality criterion. It was not significantly different between corresponding iron-deficient and control segments. To control these results in vivo mesenteric blood was collected from duodenal and jejunal segments in situ. Corresponding to in vitro findings iron transfer was close to linear over the experimental period. In iron deficient duodenal segments iron transfer increased approximately 3 times as compared to controls while no adaptational changes were found in the distal jejunum. No significant longitudinal gradient was found in the mucosal content of ferritin and nonheme iron. Both parameters were decreased in iron deficiency by about half. The mucosal transferrin content showed no longitudinal gradient in control animals. In iron deficiency transferrin was significantly increased in the duodenum and in the three most proximal jejunal segments. The results indicate that in rats adaptation of iron absorption to the demand can only be expected in the duodenum and in the proximal 20 cm of the jejunum. Because this process shows a steep gradient in the proximal small intestine, studies on the adaptation of intestinal iron transfer to the demand should use short and well-defined segments in order to provide reproducible results.
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PMID:Rat intestinal iron transfer capacity and the longitudinal distribution of its adaptation to iron deficiency. 221 95

Dietary iron deficiency in rats results in increased blood glucose turnover and recycling. We measured the rates of glucose production in isolated hepatocytes from iron-sufficient (Fe+) and iron-deficient (Fe-) rats to assess the intrinsic capacity of the Fe- liver to carry out gluconeogenesis. Low-iron and control diets were given to 21-day-old female rats. After 4-5 wk, hemoglobin concentrations averaged 4.1 g/dl in the Fe- and 14.3 g/dl in the Fe+ animals. In the hepatocytes from Fe- rats, there was a 35% decrease in the rate of glucose production from 1 mM pyruvate + 10 mM lactate, a 48% decrease from 0.1 mM pyruvate + 1 mM lactate, a 39% decrease from 1 mM alanine, and a 48% decrease from 1 mM glycerol. The addition of 5 microM norepinephrine or 0.5 microM glucagon to the incubation media produced stimulatory effects on hepatocytes from both Fe- and Fe+ rats, resulting in the maintenance of an average difference of 38% in the rates of gluconeogenesis between the two groups. Studies on isolated liver mitochondria and cytosol revealed alpha-glycerophosphate-cytochrome c reductase and phospho(enol)pyruvate carboxykinase activities to be decreased by 27% in Fe- rats. We conclude that because severe dietary iron deficiency decreases gluconeogenesis in isolated rat hepatocytes, the increased gluconeogenesis demonstrated by Fe- rats in vivo is attributable to increased availability of gluconeogenic substrates and upregulation of the pathway.
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PMID:Iron deficiency decreases gluconeogenesis in isolated rat hepatocytes. 260 20


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