氟骨症患儿血锌铁钙镁铜磷水平测定

目的了解贵州省织金县燃煤型氟中毒重病区儿童血液中锌、铁、钙、镁、铜、磷的变化情况。方法对织金县燃煤型氟中毒重病区5所小学6—15岁在校学生氟骨症患儿112例（病例组）、轻病区无氟骨症儿童92例（轻病区对照组），非病区儿童20例（健康对照组）进行血液中锌、铁、钙、镁、铜、磷及尿氟测定，并进行比较分析。结果病例组体内微量元素（锌、铁、钙、镁、铜）低于健康对照组（P〈0．05）；轻病区对照组介于病例组和健康对照组之间。重病区病例组儿童尿氟高于健康对照组，轻病区对照组介于病例组和健康对照组之间，但组间比较差异无统计学意义（P〉0．05）。病例组血磷高于健康对照组（P〈0．05）。结论高氟摄入可引起体内血锌、铁、钙、镁、铜的降低，血磷升高，同时使骨骼发生病变，严重影响儿童的生长发育。     

Inhibition of rat methylbenzylnitrosamine metabolism by dietary zinc and zinc in vitro.

Methylbenzylnitrosamine is an esophageal-specific carcinogen in the rat, and the incidence of methylbenzylnitrosamine-induced esophageal carcinoma is increased by dietary zinc deficiency. Methylbenzylnitrosamine requires activation by cytochrome P-450 to be mutagenic; the present study examined the role of dietary zinc deficiency and the in vitro addition of zinc on the cytochrome P-450-dependent microsomal metabolism of methylbenzylnitrosamine. Dietary zinc deficiency significantly increased the cytochrome P-450-dependent esophageal and hepatic microsomal metabolism of methylbenzylnitrosamine. These changes occurred without alteration in the specific content of total microsomal cytochrome P-450 of the esophagus or liver. The addition of zinc in vitro, at concentrations found in normal tissues, irreversibly inhibited the esophageal and hepatic cytochrome P-450-dependent microsomal metabolism of methylbenzylnitrosamine. These results suggest that physiological levels of zinc may be an endogenous inhibitor of methylbenzylnitrosamine metabolism. Dietary zinc deficiency appears to reduce this inhibition of cytochrome P-450 activity, resulting in an increase in carcinogen activation.     

氟铝联合对大鼠全血锌、铁、钙、镁、铜的影响

目的 探讨过量氟、铝及其联合作用对大鼠全血锌(Zn)、铁(Fe)、钙(Ca)、镁(Mg)、铜(Cu)的影响.方法 48只SD大鼠按体质量随机分为4组:对照组、高铝组、高氟组、高氟铝组,饮水含铝量分别为0,90、0.90 mg/L:饲料含氟量分别为5.2、5.2、106.0、106.0 mg/kg,含铝量分别为6.8、6.8 19.7、19.7 mg/kg;90 d后原子吸收光谱分析法测定全血Zn、Fe、Ca、Mg、Cu水平.结果 组间比较,全血含Zn、Fe、Mg、Cu量差异有统计学意义(F值分别为46.25、14.74、6.10、Z93,P<0.05),而全血含Ca量未见明显改变(F=2.81,P>0.05).析因分析显示.高铝摄入明显降低全血含Zn、Fe、Mg量(F值分别为42.66、5.41、7.04,P<0.05),高氟摄人明显降低全血含Zn、Fe、Mg、Cu量(F值分别为64.50、37.90、9.75、6.74,P<0.05),氟铝联合对全血含Zn量有交互作用(F:31.59,P<0.05),Fe、Ca、Mg、Cu均未见明显交互作用(F值分别为0.91、1.63、1.51、0.00,P>0.05).与对照组全血含Zn、Fe、Mg、Cu量[(131.30±13.86)μmol/L,(10.24±1.02)、(1.71±0.19)mmol/L,(20.43±4.42)μmol/L]比较,高铝组全血含Zn量[(90.84±9.98)μmol/L]明显降低(P<0.05),高氟组全血含Zn、Fe、Mg量[(85.85±10.92)μmol/L,(8.49±0.68)、(1.52±0.13)mmol/L]也明显降低(P<0.05),高氟铝组全血含Zn、Fe、Mg、Cu量[(82.82±11.00)μmol/L,(8.16±0.45)、(1.46±0.09)mmol/L,(15.69±2.38)μmol/L]均明显降低(P<0.05);与高铝组[(9.43±1.09)mmool/L]比较,高氟铝组全血含Fe量[(8.16±0.45)mmol/L]明显降低(P<0.05).结论 过量氟能引起全血含Zn Fe、Mg、Cu量下降,过量铝能引起全血含Zn、Fe、Mg量降低;氟铝联合对大鼠全血含Ca量无影响,仅对全血含Zn量有明显交互作用.     

Inhibition of iron absorption by cholestyramine

Recent studies have demonstrated that cholestyramine, an anionic exchange resin, binds inorganic and hemoglobin ironin vitro and inhibits the absorption of these compounds from the rat small intestine. However, these studies did not answer the question: Will prolonged cholestyramine administration cause depletion of iron stores and development of iron deficiency anemia? Accordingly, rats were fed diets of standard rat chow or standard rat chow containing either 2 or 5% cholestyramine for 6 months. In the 5% cholestyramine group the hematocrit and hemoglobin values were significantly lower as compared to controls (37.5 vs 43.6%;P<0.001) and (11.4 vs 14.2 g%;P<0.001). Serum iron values in the 5% cholestyramine groups were significantly less than the control group (158±23 vs 205±15 µg%;P<0.001). In the control group nonheme iron in the liver, spleen and duodenum was 206±31, 1482±212 and 12.5±1.1 µg/g tissue, respectively. In the 2% cholestyramine-treated group, liver nonheme iron was reduced to 172±33 µg/g, spleen nonheme iron to 1266±447 µg/g and duodenal iron to 11.7±1.0 µg/g. In the 5% cholestyramine-treated group liver nonheme iron was significantly reduced to 143±35 µg/g, spleen nonheme iron to 1030±3.4 µg/g and duodenal nonheme iron to 10.2±1.4 µg/g respectively. In addition, a significant decrease in serum vitamin B₁₂ levels was noted in cholestyramine-fed rats compared to controls (256±83 vs 404±118 µµg/ml). These data indicate that prolonged administration of cholestyramine to rats results in significantly decreased serum iron, tissue nonheme iron stores and serum vitamin B₁₂ levels associated with decreased hematocrit and hemoglobin levels.     

Maternal prenatal dietary potassium, calcium, magnesium, and infant blood pressure

We studied the association between the prenatal diets of 212 mothers assessed by a semiquantitative food frequency questionnaire and the blood pressure of their infants. Prenatal potassium, calcium, and magnesium intakes were measured and adjusted for total caloric intake. Infant blood pressure was measured at 2-3 days and at 1, 6, and 12 months of age by using an ultrasonic-auscultatory device and was adjusted for cuff size, observer, and sleep/activity status, age in days in neonates, and weight at 6 and 12 months. Maternal prenatal potassium intake was inversely related to diastolic pressure at 6 months (r = -0.28, p less than 0.01) and at 12 months (r = -0.30, p less than 0.05). After adjustment for neonatal breast versus formula feeding, maternal prenatal calcium intake was inversely related to systolic blood pressure at 1 month (r = -0.21, p less than 0.01), and to diastolic blood pressure at 6 months (r = -0.27, p less than 0.01) and 12 months (r = -0.24, p less than 0.05). Maternal prenatal magnesium intake was inversely related to 6-month systolic blood pressure (r = -0.20, p less than 0.05). In multivariable models with all three cations, maternal prenatal potassium intake was independently and inversely related to diastolic blood pressure at 6 and 12 months. Maternal prenatal calcium intake was independently related to 1-month systolic and 6-month diastolic blood pressure. Age-specific infant blood pressure differences between the upper and lower quartiles of maternal prenatal cation intakes ranged from 3 to 7 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of penicillamine therapy on the concentration of zinc, copper, iron, calcium and magnesium in the serum and their excretion in urine

The application of Penicillamine (750 mg per day) for one year resulted in the expected increase of urinary copper excretion (8-10 fold). The increase of Zinc excretion was only moderate (2 fold). The application of Penicillamine did not influence the excretion of Ca, Mg and Fe. We did not find a decrease of Zinc content in the hair of patients after one year treatment. The serum concentration of Zn, Cu, Fe, Ca and Mg was not influence by the application of Penicillamine. Thus, a treatment with Penicillamine is not a probable cause of zinc deficiency in liver disease.     

Preventing oxidative stress in rats with aldosteronism by calcitriol and dietary calcium and magnesium supplements

BACKGROUND: Prominent features of the clinical syndrome of congestive heart failure (CHF) include aldosteronism and the presence of oxidative stress. Secondary hyperparathyroidism (SHPT) accompanies aldosteronism due to increased urinary and fecal excretion of Ca. SHPT accounts for intracellular Ca overloading of diverse cells, including peripheral blood mononuclear cells (PBMC), and the appearance of oxidative stress. Parathyroidectomy or a Ca channel blocker each prevent these responses. Herein, we hypothesized calcitriol, or 1,25(OH)2D3, plus a diet supplemented with Ca and Mg (CMD) would prevent SHPT and Ca overloading of PBMC and thereby oxidative stress in these cells in rats receiving aldosterone/salt treatment (ALDOST). METHODS AND RESULTS: In rats with ALDOST for 4 weeks, without or with CMD, we monitored plasma-ionized [Ca]o and parathyroid hormone (PTH), and PBMC cytosolic-free [Ca]i and H2O2 production. Untreated, age- and gender-matched rats served as controls. Compared to controls, ALDOST led to an expected fall in plasma [Ca]o level with accompanying rise in plasma PTH level and intracellular Ca overloading of PBMC and their increased production of H2O2. CMD prevented SHPT and abrogated intracellular Ca overloading of PBMC and their increased H2O2 production. CONCLUSIONS: The appearance of SHPT in aldosteronism, induced by fallen plasma [Ca]o, leads to PTH-mediated Ca overloading of PBMC and their increased production of H2O2. SHPT in rats with aldosteronism can be prevented by calcitriol and a diet supplemented with Ca and Mg. These findings raise the prospect that the SHPT found in CHF could be managed with macro- and micronutrients.     

Calcium metabolism and dietary calcium in salt sensitive hypertension

Evidence has accumulated over the past decade that suggests a relationship between low calcium intake, abnormalities in cation metabolism and hypertension in certain segments of the essential hypertension population. This evidence has been developed from epidemiological data, calcium intervention trials and observations related to biochemical alterations suggestive of a calcium deficiency in certain patients with hypertension and in animal models of essential hypertension. It is becoming increasingly evident that salt sensitive individuals are especially likely to be characterized by abnormalities of calcium metabolism and blood pressure responses to dietary calcium. In this review the role of calcium in the regulation of blood pressure is examined with an emphasis on epidemiological, biochemical, hemodynamic and dietary intervention data in the salt sensitive hypertensive patient.     

Serum copper, magnesium, zinc, calcium, and potassium changes following acute myocardial infarction

When analyzed within seventy-two hours of admission to the coronary care unit, the mean values of serum copper and magnesium were lower in patients with acute myocardial infarction than in noncardiac patients. Zinc values showed no difference. Because the reduction of serum copper in males was statistically significant, the authors suggest that a lowering of serum copper, especially in males, can be useful in the diagnosis of recent infarction and could possibly have other implications. Significant elevations of serum calcium and of serum potassium were also demonstrated.     

Association of dietary calcium,phosphorus, and magnesium intake with caries status among schoolchildren

The aim of this study was to investigate the associations between caries experience and daily intake of calcium (Ca), phosphorus (P), magnesium (Mg), and Ca/P ratio. A total of 2248 schoolchildren were recruited based on a population-based survey. Each participant received a dental examination and questionnaire interviews about the 24-hour dietary recalls and food frequency. The daily intake of Ca, P, Mg, and Ca/P ratio were inversely associated with primary caries index, but only the Ca/P ratio remained significant after adjusting for potential confounders. According to the Taiwanese Dietary Reference Intakes, the Ca/P ratio was related to both caries in primary teeth (odds ratio = 0.52, p = 0.02) and in permanent teeth (odds ratio = 0.59, p = 0.02). The daily intakes of Ca/P ratio remained an important factor for caries after considering potential confounding factors.     

Effect of penicillamine and zinc on iron metabolism in Wilson's disease

OBJECTIVE: The physiology of iron metabolism in Wilson's disease is largely unknown, and there is a paucity of data on the real presence and progression of iron accumulation. The purpose of this study was to assess the iron metabolism parameters, including hepatic iron concentration, in follow-up liver biopsies and serum, and urinary pro-hepcidin. MATERIAL AND METHODS: Twenty-three Wilson's disease patients undergoing long-term treatment were enrolled in the study. RESULTS: Hepatic iron content was significantly increased in penicillamine-treated patients compared with zinc-treated patients. Serum and urinary pro-hepcidin concentrations were significantly higher in Wilson's disease patients than in healthy volunteers, despite a normal biochemical pattern of iron metabolism. CONCLUSIONS: Long-term penicillamine treatment seems to be responsible for a more marked iron accumulation in the liver. This observation may justify a revision of long-term Wilson's disease treatment modalities with penicillamine. The finding that serum and urinary pro-hepcidin is significantly increased in Wilson's disease patients compared with healthy volunteers suggests a role for hepcidin in iron metabolism in Wilson's disease, but this needs to be confirmed by a study of hepatic hepcidin expression in these patients.