Effects of iron therapy on blood lead concentrations in infants

To determine whether blood lead concentration is elevated in iron-deficient infants, blood lead and serum ferritin concentrations, serum iron/transferring iron-binding capacity (Fe/TIBC) and complete blood counts were measured in 30 iron deficient and 35 control infants, aged 6–24 months. All 30 iron-deficient infants received iron supplementation (ferric hydroxide-polymaltose complex, 6 mg/kg Fe³⁺/day) for 1–6 months. Blood lead concentrations were measured in 18 of the iron deficient infants after their ferritin levels returned to the normal range. The geometric mean blood lead concentration was higher in iron deficient than in control infants (1.846 vs. 1.416 μg/dL). After iron therapy, the blood lead levels of iron-deficient infants decreased significantly compared with pre-treatment levels (1.785 vs. 2.386 μg/dL), and the hemoglobin and ferritin concentrations increased significantly. These findings indicate that iron deficiency increases blood lead concentrations in infants with very low blood lead concentrations.     

Effects of chronic sleep deprivation on glucose homeostasis in rats

Sleep and Biological Rhythms - Epidemiological studies have shown that chronic sleep disturbances resulted in metabolic disorders. The purpose of this study was to assess the relationship between...     

The relationship between iron status and lead absorption in rats

The absorption of lead from loops of small intestinein situ was investigated in rats in which iron absorption was increased by stimuli varying in type, intensity, or duration. Lead absorption was increased by a short period of severe iron restriction before any change in hematological indices became apparent. A period of hypoxia, which markedly increased iron absorption, did not influence absorption of lead. An extended period of moderate iron restriction resulted in a marked reduction in liver iron stores and increased iron absorption throughout the 17-wk experiment. Under these conditions lead absorption was initially also increased, but after 12 wk, when iron intake had become adequate to meet essential requirements, lead absorption was similar to that in iron-supplemented rats. These results are discussed in the light of evidence for a receptor-mediated absorption process for iron.     

Effects of iron deficiency and exercise on myoglobin in rats

The effects of iron deficiency and endurance training on muscle myoglobin (Mb), body weights, and blood lactic acid concentration were studied in rats. Fifty animals were divided into four groups: anemic trained (AT), normal trained (NT), anemic sedentary (AS), and normal sedentary (NS). Following 5 weeks of dietary control, the mean hemoglobin values for the AT and AS rats were 0.013 +/- 0.002 mmol X l-1 (8.7 +/- 1.4 g X dl-1) and 0.014 +/- 0.003 mmol X l-1 (9.2 +/- 1.7 g X dl-1) respectively, and did not significantly change throughout the study. AT and NT rats were run on a motor driven treadmill 4 days/week for 6 weeks up to a pre-established time of 90 min. Following the training, body weights of the AT (157 +/- 13 g) and NT (153 +/- 13 g) rats were lower than their respective sedentary groups AS (172 +/- 9 g) and NS (176 +/- 15 g). Resting blood lactic acid concentration following training was lower in both trained groups, AT (3.3 +/- 2.0 mM) and NT (2.3 +/- 1.9 mM) compared to AS (8.2 +/- 2.6 mM) and NS (3.8 +/- 1.6 mM). Training increased Mb concentration in hearts of both the anemic and normal trained groups (AT, 0.66 +/- 0.13 mg X g-1; NT, 0.95 +/- 0.08 mg X g-1) compared to the sedentary groups (AS, 0.44 +/- 0.08 mg X g-1; NS, 0.70 +/- 0.13 mg X g-1). Only the AT rats showed an increase in skeletal muscle Mb. This study provides evidence that myoglobin may limit aerobic metabolism.     

快速眼动睡眠剥夺对大鼠线索性恐惧消退再现的影响

目的：研究RSD对大鼠线索性恐惧消退再现的影响。方法：1d大鼠适应环境;2d进行恐惧条件化;3d恐惧消退训练并进行RSD;4d进行恐惧消退再现检测。结果：在恐惧条件化及消退训练阶段,0-6hRSD组、6—12hRSD组与各自对照组大鼠的僵直水平组间差异都无显著性;在恐惧消退再现检测阶段,0-6hRSD组大鼠的僵直水平显著高于对照组,6-12hRSD组与对照组大鼠的僵直水平组间差异无显著性。结论：RSD损害消退记忆的再现,并且依赖于睡眠剥夺的时段。     

Mode of action of iron on arylsulphatases under acute lead acetate treated conditions in rats

Arylsulphatases A, B and C were found to be inhibited in liver and kidney tissues under lead acetate-treated conditions (both in vivo and in vitro) in rats. When lead acetate-treated animals (in vivo) were supplemented with ferric ammonium citrate (in vivo), a remarkable recovery was found in the activities of all arylsulphatases A, B and C whereas ferric ammonium citrate itself had no effect on the activities of arylsulphatases. When both the in vivo and in vitro lead acetate-treated arylsulphatases were supplemented with the purified ferritins (in vitro) it was observed that lead-induced inhibition of the activities of arylsulphatases was successfully reversed. It was also found that ferritins were able to bind a large quantity of lead. These results indicated that ferritins were directly involved for reactivation of arylsulphatases which were inhibited by lead. It was well established that a response to iron administration in rats was an immediate de novo stimulation of ferritin biosynthesis. Iron might therefore protect the enzymatic activities of arylsulphatases by enhancing the level of ferritin in liver and kidney tissues which is known to bind a large quantity of lead thereby ameliorating their toxic effects in the living system.     

Effects of calcium deprivation on n-6 fatty acid metabolism in growing rats

Two separate experiments examining the effects of calcium deficiency on plasma and liver fatty acids in rats were conducted. In Experiment I, weanling male Sprague-Dawley rats were fed a calcium-deficient diet with or without the supplementation of 5 or 20 g/kg calcium for 22 days. There were no significant differences in plasma and liver fatty acid distribution between the two calcium-supplemented groups. However, calcium deficiency significantly elevated the levels of 18:3n-6 in plasma and liver cholesteryl esters and liver phospholipids, while it reduced the levels of 20:3n-6 in plasma cholesteryl esters. In Experiment II, weanling rats were fed a calcium-deficient diet supplemented with 5 g/kg calcium for 22 days. After overnight fast, animals were given by intragastric feeding a dose of 4 g/kg body wt gamma-linolenic acid concentrate (containing 92% 18:3n-6 ethyl ester), and were killed 22 hr later. The levels of 18:3n-6 were significantly higher, whereas the levels of 20:3n-6 were either not changed or lower than those in calcium-supplemented group. In both experiments, the ratios of (20:3n-6 + 20:4n-6)/18:3n-6 in plasma and liver lipids were significantly reduced in calcium-deficient rats. These results suggest that calcium may play an important and specific role in the process of elongation of 18:3n-6 to 20:3n-6.     

外源铁对铅污染土壤中宽叶香蒲铅积累的影响

采用温室盆栽方法,研究添加外源铁对不同铅浓度(0、100、500和1000 mg·kg-1)污染土壤中宽叶香蒲铅积累的影响.结果表明:各铅浓度条件下,与添加100 mg Fe·kg-1相比,添加500 mg Fe·kg-1处理的宽叶香蒲地上部和根的铅含量均增高.土壤铅浓度为1000mg·kg-1时,添加500 mg Fe·kg-1处理根的铅含量比100 mg Fe·kg-1处理增加33.7％,地上部铅含量增加50.5％.添加500 mg Fe·kg-1处理的根际土壤中可交换态铅比100mg Fe·kg-1处理增加77.0％～114.6％.除500 mg·kg-1铅浓度外,各铅浓度条件下添加500mg Fe·kg-1处理根干质量均显著低于100 mg Fe·kg-1处理.在铅污染的湿地环境中添加适量铁可以提高铅的有效性,促进铅积累.     

Effects of lead poisoning on properties of brain mitochondria in young rats

When the litters were 14 days old, wistar rat pups received lead ions. The suckling mother was fed by a powdered laboratory chow containing lead carbonate (1%, 2%, 4%). The intoxication was going on for 3 days to 9 weeks. While lead-fed pups showed a decrease in body-weight gain and in neurologic development, lead ions were without effects on oxygen consumption, ADP-phosphorylation and activity of several enzymes of cerebral mitochondria. On the other hand, the important lead accumulation into cerebral mitochondria was in a straight ratio with lead doses in the feedings. To explain the in vivo data, the effects of lead acetate were investigated in vitro on brain mitochondria of young male wistar rats. Our findings indicate that lead ions alter mitochondrial respiration and ADP-phosphorylation and that inorganic phosphate has a protective effect.     

快速眼动睡眠剥夺对大鼠恐惧消退再现的影响

目的：研究两种实验范式AAA和ABA（A、B表示不同场景）中快速眼动睡眠剥夺（RSD）对大鼠恐惧消退再现的影响。方法：1d大鼠适应环境;2d进行恐惧条件化;3d恐惧消退训练并进行RSD;4d进行恐惧消退再现检测。结果：AAA实验范式中,在恐惧消退再现检测阶段,0～6hRSD组大鼠的僵直水平显著高于对照组（P〈0．05）,其他阶段处理组与对照组大鼠的僵直水平都无显著性;ABA实验范式中,各阶段处理组与对照组大鼠的僵直水平都无显著性。结论：不同实验范式中RSD对恐惧消退影响不同,并且这种影响依赖于睡眠剥夺的时段。     

长期游泳运动对大鼠铁状态的影响

目的：观察不同的运动时间对铁状态的影响。方法：大鼠随机分为3、6、12个月的三个游泳运动组和相应安静组;运动期满后观察血液学铁状态指标和器官非血红素铁(NHI)含量和NHI总含量(TNHI)的变化。结果：与安静组相比,三种不同时间长度的运动均诱导一种具有血浆铁浓度降低、血浆转铁蛋白铁饱和度降低而血红蛋白浓度和红细胞比容得到雏持的血液学低铁状态;这种低铁状态伴有肝、脾、心、肾NHI浓度显著降低,但与运动时间无关;肝、脾和肾TNHI变化与其浓度变化方向一致,但心脏没有显著变化;上述器官TNHI随时间增加而增多。结论：尽管运动诱导的低铁状态类似于铁缺乏中期表现,但由于器官NHI重分布和铁贮存并没有进行性降低,因此,长期运动引起的低铁状态可能是机体内铁代谢对运动的适应,不存在所谓“运动性铁缺乏”现象。     

Effects of food deprivation on daily changes in body temperature and behavioral thermoregulation in rats

Homeothermic animals regulate body temperature (T(b)) by using both autonomic and behavioral mechanisms. In the latter process, animals seek out cooler or warmer places when they are exposed to excessively hot or cold environments. Thermoregulation is affected by the state of energy reserves in the body. In the present study, we examine the effects of 4-day food deprivation on circadian changes in T(b) and on cold-escape and heat-escape behaviors in rats. Continuous measurement of T(b) during food deprivation indicated that the peak T(b) amplitude was not different from baseline values, but the trough amplitude continuously decreased after the onset of food deprivation. Cold-escape behavior was facilitated by food deprivation, whereas heat-escape behavior was unchanged. After the termination of food deprivation, the lowered T(b) returned to normal on the first day. However, cold-escape behavior was still facilitated on the third day after food reintroduction. Autonomic and behavioral thermoregulatory effectors are modulated in the face of food shortage so as to maintain optimal performance during the active period, whereas increasing energy conservation occurs during the quiescent phase.