Showing papers on "Lead acetate published in 2011"

Acetylcholinesterase activity and antioxidant capacity of zebrafish brain is altered by heavy metal exposure

Abstract: Pollution is a world problem with immeasurable consequences. Heavy metal compounds are frequently found as components of anthropogenic pollution. Here we evaluated the effects of the treatment with cadmium acetate, lead acetate, mercury chloride, and zinc chloride in acetylcholinesterase activity and gene expression pattern, as well as the effects of these treatments in antioxidant competence in the brain of an aquatic and well-established organism for toxicological analysis, zebrafish (Danio rerio, Cyprinidae). Mercury chloride and lead acetate promoted a significant decrease in acetylcholinesterase activity whereas they did not alter the gene expression pattern. In addition, the antioxidant competence was decreased after exposure to mercury chloride. The data presented here allowed us to hypothesize a signal transmission impairment, through alterations in cholinergic transmission, and also in the antioxidant competence of zebrafish brain tissue as some of the several effects elicited by these pollutants.

The redox status in rats treated with flaxseed oil and lead-induced hepatotoxicity.

Abstract: Lead is a persistent environmental pollutant, and its toxicity continues to be a major health problem due to its interference with natural environment. In the present study, we have evaluated the effect of flaxseed oil on lead acetate-mediated hepatic oxidative stress and toxicity in rats. Lead acetate enhanced lipid peroxidation and nitric oxide production in both serum and liver with concomitant reduction in glutathione, catalase, superoxide dismutase, glutathione reductase, glutathione-S-transferase, and glutathione peroxidase activities, these findings were associated with DNA fragmentation. In addition, lead acetate caused liver injury as indicated by histopathological changed of the liver with an elevation in total bilirubin, serum alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transpeptidase, and alkaline phosphatase. Treatment of rats with flaxseed oil resulted in marked improvement in most of the studied parameters as well as histopathological features. On the basis of the above results it can hypothesized that flaxseed oil is a natural product can be protect against lead acetate-mediated hepatic cytotoxicity.

Antioxidant effects of Etlingera elatior flower extract against lead acetate - induced perturbations in free radical scavenging enzymes and lipid peroxidation in rats

Abstract: Etlingera elatior or 'pink torch ginger' (Zingiberaceae) are widely cultivated in tropical countries and used as spices and food flavoring. The purpose of this study was to evaluate the antioxidant effects of Etlingera elatior against lead - induced changes in serum free radical scavenging enzymes and lipid hydroperoxides in rats. Rats were exposed to lead acetate in drinking water (500 ppm) for 14 days alone or plus the ethanol extract of E. elatior (50, 100 and 200 mg/kg). Blood lead levels, lipid hydroperoxides, protein carbonyl contents and oxidative marker enzymes were estimated. Lead acetate in drinking water elicited a significant increase in lipid hydroperoxides (LPO) and protein-carbonyl-contents (PCC). There was a significant decrease in total antioxidants, superoxide dismutase, glutathione peroxidase and glutathione S-transferase levels with lead acetate treatment. Supplementation of E. elatior was associated with reduced serum LPO and PCC and a significant increase in total antioxidants and antioxidant enzyme levels. The results suggest that flower extract of Etlingera elatior has powerful antioxidant effect against lead - induced oxidative stress and the extract may be useful therapeutic agent against lead toxicity. However, detailed evaluations are required to identify the active antioxidant compounds from this plant extract.

Acute lead exposure increases arterial pressure: role of the renin-angiotensin system.

Abstract: Background Chronic lead exposure causes hypertension and cardiovascular disease. Our purpose was to evaluate the effects of acute exposure to lead on arterial pressure and elucidate the early mechanisms involved in the development of lead-induced hypertension. Methodology/Principal Findings Wistar rats were treated with lead acetate (i.v. bolus dose of 320 µg/Kg), and systolic arterial pressure, diastolic arterial pressure and heart rate were measured during 120 min. An increase in arterial pressure was found, and potential roles of the renin-angiotensin system, Na+,K+-ATPase and the autonomic reflexes in this change in the increase of arterial pressure found were evaluated. In anesthetized rats, lead exposure: 1) produced blood lead levels of 37±1.7 µg/dL, which is below the reference blood concentration (60 µg/dL); 2) increased systolic arterial pressure (Ct: 109±3 mmHg vs Pb: 120±4 mmHg); 3) increased ACE activity (27% compared to Ct) and Na+,K+-ATPase activity (125% compared to Ct); and 4) did not change the protein expression of the α1-subunit of Na+,K+-ATPase, AT1 and AT2. Pre-treatment with an AT1 receptor blocker (losartan, 10 mg/Kg) or an ACE inhibitor (enalapril, 5 mg/Kg) blocked the lead-induced increase of arterial pressure. However, a ganglionic blockade (hexamethonium, 20 mg/Kg) did not prevent lead's hypertensive effect. Conclusion Acute exposure to lead below the reference blood concentration increases systolic arterial pressure by increasing angiotensin II levels due to ACE activation. These findings offer further evidence that acute exposure to lead can trigger early mechanisms of hypertension development and might be an environmental risk factor for cardiovascular disease.

Protective Effect of Chlorella vulgaris against Lead-Induced Oxidative Stress in Rat Brains

Abstract: Lead (Pb) is a toxic heavy metal widely distributed in the environment. Recent studies suggest oxidative stress as one possible mechanism involved in Pb poisoning. The unicellular algae Chlorella vulgaris (CV) contains various bioactive substances with antioxidant for the prevention of oxidative stress by metals. We investigated the protective effects of CV on the oxidative system in five groups of male Sprague-Dawley rats fed American Institute of Nutrition (AIN)-76 diet, plus 2, 5 or 10% CV for 4 weeks. All animals were exposed to 200 mg/l lead acetate by drinking water except for the control (tap water). Body weight gains were significantly reduced in the Pb-exposed group (64%) relative to the control and CV groups. Brain weights were significantly increased in the Pb-exposed group (44%) relative to the others. In the experimental period, food intake, water intake and Pb intake were not different among the groups. The levels of Pb (87%) in brain obtained from the Pb-exposed group were significantly increased compared to the other groups. The levels of oxidative stress parameters in the brain such as superoxide dismutase (36%), glutathione peroxidase (63%), and glutathione reductase (30%) were decreased in the Pb-exposed group relative to the control but markedly increased in the CV groups. The CV also significantly increased glutathione levels by approximately 1.7-fold over the Pb-exposed group, while the malondialdehye concentration significantly decreased by approximately 47-71%. Based on these results, we found alterations in several indicators of oxidative stress of Pb intoxication, suggesting the antioxidant potential of CV. Therefore, CV may have protective effects on brain damage of low-level and short-term Pb exposure in the brains of rats.

Exercise Training and Antioxidants: Effects on Rat Heart Tissue Exposed to Lead Acetate

Abstract: We have investigated the cardioprotective effects of exercise training and/or curcumin on lead acetate-induced myocardial damage. Forty rats were randomly divided into 5 groups: (1) lead acetate, (2) curcumin, (3) endurance training, (4) training + curcumin, (5) sham groups. The rats in groups 3 and 4 experienced the treadmill running of 15 to 22 m/min for 25 to 64 minutes, 5 times a week for 8 weeks. Groups 1 to 4 received lead acetate (20 mg/kg), the sham group received curcumin solvent (ethyl oleat), and the curcumin and training + curcumin groups received curcumin solution (30 mg/kg) intraperitoneally. Lead administration resulted in significant increases in high-sensitivity C-reactive protein (hs-CRP), creatine kinase-MB (CK-MB), malondialdehyde (MDA), and low-density lipoprotein (LDL), and significantly decreased glutathione peroxidase (GPx), Total Antioxidant Capacity (TAC), and high-density lipoprotein (HDL) levels. Treadmill running and\or curcumin supplementation resulted in a significant decrease in hs-CRP, CK-MB, MDA, and LDL levels and significantly increased GPx, TAC, and HDL levels. These results suggest a lifestyle-induced cardioprotective potential in ameliorating lead-induced cardiotoxicity.

Effects of Flaxseed Oil on Lead Acetate-Induced Neurotoxicity in Rats

Abstract: It is well known that chronic exposure to lead (Pb+2) alters a variety of behavioral tasks in rats and mice. Here, we investigated the effect of flaxseed oil (1,000 mg/kg) on lead acetate (20 mg/kg)-induced brain oxidative stress and neurotoxicity in rats. The levels of Pb+2, lipid peroxidation, nitric oxide (NO), and reduced glutathione (GSH) and the activity of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione-S-transferase (GST), and glutathione peroxidase (GPx) were determined in adult male albino rats. The level of Pb+2 was markedly elevated in brain and blood of rats. This leads to enhancement of lipid peroxidation and NO production in brain with concomitant reduction in GSH, CAT, SOD, GR, GST, and GPx activities. These findings were associated with DNA fragmentation. In addition, lead acetate induced brain injury as indicated by histopathological changes of the brain. Treatment of rats with flaxseed oil resulted in marked improvement in most of the studied parameters as well as histopathological features. These findings suggest to the conclusion that flaxseed oil significantly decreased the adverse harmful effects of lead acetate exposure on the brain as well as Pb+2-induced oxidative stress.

Molecular and biochemical studies on the effect of gamma rays on lead toxicity in cowpea (Vigna sinensis) plants

Abstract: The effect of lead acetate in the presence or absence of cowpea seeds irradiated with gamma rays on morphological criteria, protein electrophoresis, isozymes, and random amplification of polymorphic DNA-polymerase chain reaction (RAPD-PCR) of leaves was investigated. A highly significant decrease in shoot and root length was observed upon lead acetate exposure (300 and 600 μM). On the other hand, in seeds irradiated with gamma rays (2, 5, and 8 krad), these morphological parameters were increased after lead acetate treatments. Meanwhile, all treatments (lead acetate and gamma rays) caused variations in number, intensity, and/or density of SDS electrophoretic bands of proteins. In addition, electrophoretic studies of esterase, acid phosphatase, peroxidase, polyphenol oxidase, catalase, and superoxide dismutase isozyme activities were increased with increasing the concentrations of lead acetate and gamma ray doses. The variation in DNA profile in response to lead acetate and gamma irradiation treatments was detected by RAPD-PCR technique. The result of RAPD analysis using the five primers indicated the appearance and disappearance of DNA polymorphic bands at all treatments (gamma rays and lead stress). The relatively high concentrations of lead acetate (600 μM) induced more changes in genomic DNA pattern.

Effect of Long-term Exposure to Low or Moderate Lead Concentrations on Growth, Lipid Profile and Liver Function in Albino Rats

Abstract: 5 Abstract: Effect of long-term exposure to low or moderate lead acetate (PbAc) on growth, serum lipid profile and some biochemical parameters was investigated. Male albino rats were divided into five groups and given 0, 0.025, 0.05, 0.1 and 0.3% PbAc in drinking water for 11 months. There was a significant decrease in body weight in rats given 0.1 % PbAc at the third month of lead treatment (p<0.01) compared to the control group, while the body weight gain was significantly increased at the end of experiment in animals exposed to 0.05 % PbAc (p<0.05). Serum concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride remain unchanged in all lead exposed groups compared to the control group. Similarly, no significant alteration was observed in serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase activities and glycemia in all lead treated groups. In conclusion, the long-term exposure to low lead concentration may conduct to high weight gain and obesity risk. However, no evident for disturbance of serum lipid profile or biochemical liver parameters was observed after long-term lead exposure. Therefore, long term-exposure to low or moderate lead concentrations should not be incriminated to risk of atherosclerosis or impairment of liver function.

Toxicity bioassay of lead acetate and effects of its sub- lethal exposure on growth, haematological parameters and reproduction in Clarias gariepinus

Abstract: The African catfish, Clarias gariepinus , was exposed to different concentrations of lead acetate for 96 h, and the value of LC 50 for the exposure period was registered as 122 mg/L. The effects of sub-lethal exposure on growth, reproduction and haematological parameters were also investigated in C. gariepinus . Lead exposure at all concentrations reduced growth rate, and was inversely related to growth. There were significant effects of lead exposure on erythrocyte count, haemoglobin concentration and haematocrit values. Lead exposure time and dose increased the plasma glutamicoxaloacetic transaminase (PGOT) and plasma glutamic-pyruvic transaminase (PGPT) activity levels. No significant effect of lead acetate was noticed on fecundity and ovum size. Sperm motility was reduced in all concentrations of lead acetate after 4 weeks of exposure. The present investigation indicates that the lead acetate is less toxic to fish than other metals as the LC 50 value is comparatively high.

Efficacy of Allicin in Decreasing Lead (Pb) Accumulation in Selected Tissues of Lead-Exposed Common Carp (Cyprinus carpio)

Abstract: The objective of this study was to evaluate the effects of allicin, the main biologically active component of garlic clove extracts, on lead levels in different common carp tissues including liver, kidney, brain, bone, and blood following experimental lead poisoning Fish were divided randomly into five groups depending on the combination of lead acetate and allicin treatments Lead acetate exposure (70 mgL−1, 10 days) caused a significant increase in mean Pb concentrations in all examined tissues in comparison to control unexposed fish (p < 0 001) The results showed that allicin supplementation is effective in decreasing lead accumulation in all examined tissues of common carp The promising ameliorative effects of allicin on tissue lead levels of common carp make it a good candidate for therapeutic intervention of lead poisoning However, more studies are required to elucidate the pharmacokinetic effects of allicin and also molecular basis of the ameliorative properties of allicin in lead poisoning

Synthesis and characterization of lead oxide nano-powders by sol–gel method

Abstract: Our goal in this research was to obtain lead oxide nano-powders by sol–gel method. In this method, lead oxide nano-powders were synthesized through the reaction of citric acid (C6H7O8·H2O) solution and lead acetate [Pb(C2H3O2)2] solution as stabilizer and precursor, respectively. The effect of different parameters including calcination temperature, (molar ratio of citric acid to lead acetate) and drying conditions were investigated. The prepared lead oxide nano-powders were characterized by FT-IR spectroscopy, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. The prepared PbO samples consist of the particles in the range of 50–120 nm or the thick plate like structures with thickness of 53 nm depending on the drying conditions.

The potential role of flaxseed oil on lead acetate- induced kidney injure in adult male albino rats

Abstract: +2 caused injury, as revealed by some improvement in the histological structure of kidney as well as the restoration of the body weights loss of Pb +2 treated animals. At the same time, flaxseed oil decreased the levels of serum creatinine, blood urea nitrogen, uric acid, lipid peroxidation and nitric oxide production with concomitant elevation in glutathione, catalase, superoxide dismutase, glutathione reductase, glutathione-S-transferase and glutathione peroxidase activities. Thus, this study suggests the possibility of flaxseed oil usefulness in limiting toxicant induced by environmental heavy metals.

Effect of Punica granatum (pomegranate) on sperm production in male rats treated with lead acetate.

Abstract: The present study was designed to determine whether the treatment with an ethanolic extract of pomegranate (EEP) (Punica granatum) can be useful for the treatment of the deleterious effect of lead acetate (LA) administration on sperm production in rats. The effects of EEP were compared with those of ascorbic acid (AA) that is a strong antioxidant and has been shown to reverse lead-induced damage on the reproductive system.The rats were divided into five different groups: those received distilled water (control group), LA, LA with EEP, LA with AA, and EEP alone, respectively.LA administration inhibited spermatogenesis by reducing the length of the stages related to spermiation (VII and VIII) and onset of mitosis (IX–XI). LA-treated rats also showed a reduction in epididymal sperm number and daily sperm production (DSP). Administration of EEP or AA resulted in longer VIII and IX–XI stages when compared with LA-treated rats. Moreover, EEP and AA administration reduced the deleterious effect of LA on DSP and ...

The effect of lead acetate toxicity on experimental male albino rat.

Abstract: The toxic effect of Pb ion (lead acetate) was investigated using male albino rats, which was ingested at 1/20, 1/40, and 1/60 sublethal doses. Relative to normal control, the ingestion of Pb(2+) induced significant stimulation in ALT and AST activity. In addition, total soluble protein and albumin contents of plasma were decreased, while the content of globulin was changed by the Pb(2+) treatments. The cholinesterase activity was inhibited, but the activities of alkaline and acid phosphates as well as lactate dehydrogenase were stimulated as a result of lead acetate intoxication. These observations were gradually paralleled across the experiment dose of the three doses of intoxicated Pb(2+). In the case of blood picture, Pb(2+) ingestion significantly reduced the contents of hemoglobin and RBC count of intoxicated rat's blood, while the plasma levels of T3 and T4 and blood WBC count were insignificantly decreased or unchanged. All results of the present study showed that the Pb(2+) ingestion was more effective in the case of the high dose (1/20 LD(50)) than that of the low dose (1/60 LD(50)) ingestion relative to the normal healthy control. The results of the present work advice the need to avoid exposure of humans to the lead compound to avoid injurious hazard risk.

Effects of chronic lead acetate exposure on bone marrow lipid peroxidation and antioxidant enzyme activities in rats

Abstract: Occupational and environmental exposure of lead (Pb) is a serious health problem in developing and industrialized countries around the world. Toxic effect of lead is closely related to its accumulation in important tissues after its absorption into the blood. Present study looked into the effect of lead toxicity on bone marrow oxidative biomarkers in Sprague-Dawley rats. Rats were divided into four groups and in three experimental groups, they were given lead acetate in drinking water for 21 days in three different doses (200, 400 and 600 ppm). Effect of lead acetate on bone marrow lipid peroxidation and antioxidant enzymes were examined. Lead exposure for 21 days resulted in a significant increase (P<0.05) in lipid hydroperoxides and protein carbonyl contents of bone marrow and there was significant decrease (P<0.05) in bone marrow total antioxidants and superoxide dismutase, glutathione peroxidase and catalase enzyme levels. More significant increase (P<0.05) in lipid peroxidation and a decrease in antioxidant enzymes level were recorded with 600 ppm dose of lead. There was also a significant level of perturbations (P<0.05) in bone marrow antioxidant enzyme levels with low level of lead exposure for 21 days. Thus, the study confirms that exposure to lead will result in significant amount of toxic effect in the bone marrow, resulting in increased lipid peroxidation and depletion of antioxidant enzymes. Key words: Lead acetate, Lead toxicity, oxidative stress, bone marrow, lipid peroxidation.

Investigating the effect of lead acetate on rat bone marrow-derived mesenchymal stem cells toxicity: role of apoptosis.

Abstract: Lead exposure continues to be a significant public health problem. Osteoporosis, inhibition of fracture healing, and cartilage functional impairment have been reported from lead exposure. Mesenchymal stem cells (MSCs) are a bone marrow population of cells with the ability to differentiate into various cell types, particularly osteocytes and chondrocytes. Despite intensive investigation on the effect of lead poisoning on various cell types, there is very little if any report on the effect of lead on MSCs. The aim of this study, therefore, was to investigate the effect of lead acetate on rat bone marrow derived MSCs toxicity and its mechanism by examining the role of pro- and anti-apoptotic proteins in this process. It was revealed that lead acetate could induce cell death in a dose-dependent manner using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium (MTT) assay. Compared to controls, the significant over-expression of pro-apoptotic proteins, including Bax, caspases-9, -3, and p53, with no significant change in anti-apoptotic Bcl(2) protein were obtained in lead-treated cells using western blotting analysis. There was a significant increase in DNA fragmentation in treated MSCs compared to controls using flow-cytometry. Finally, it might be concluded that lead acetate could induce cell toxicity and apoptosis in MSCs, causing instability in mitochondria and in turn activation of the intrinsic pathway including over-expression of Bax, caspase 9 and caspase 3, leading to DNA damage and activation of P53.

The effects of lead acetate on sexual behavior and the level of testosterone in adult male rats.

Abstract: Background In the present study, the oral effect of lead acetate on the parameters related to sexual behavior as well as changes in the level of testosterone hormone in adult male rats have been investigated. Materials and Methods Forty adult male Wistar rats were allocated into five equal groups. The control group received nothing, the sham group received distilled water and the experimental groups received 25, 50 and 100mg/kg lead acetate orally, respectively for 28 days. The changes in testosterone hormone level and following sexual behavior parameters were investigated: mount latency (ML), intromission latency (IL), post ejaculatory interval (PEI), mount frequency (MF), ejaculatory latency (EL), intromission frequency (IF), copulatory efficacy (CE) and intercopulatory interval (ICI). Results The levels of testosterone hormone in the groups that received 50 and 100 mg/kg lead acetate showed significant decreases in compared to the control group. Additionally, the same doses of lead acetate caused significant increases in ML, IL, PEI and EL compared to the control group. No significant change was observed in MF, but a significant decrease was detected in IF and CE in the experimental group that received 100 mg/kg lead acetate when compared with the control group. ICI showed significant decreases in the experimental groups that received 50 and 100 mg/kg lead acetate compared to the control group. Conclusion It can be concluded that ingestion of lead acetate affects some behavioral activities and the testosterone level of male rats. These effects might be conducted via the alteration of leydig cells following lead acetate poisoning.

Protective role of ginger on lead induced derangement in plasma testosterone and luteinizing hormone levels of male Sprague Dawley rats.

Abstract: Background : Lead is one of the most serious environmental threats to human health especially in developing countries. It damages multiple body systems including the reproductive system. Ginger’s antioxidant and androgenic activity is reported in multiple animal studies. The aim of this study was to investigate the ameliorative effect of Zingiber officinale (ginger) on lead induced derangement in plasma testosterone and luteinizing hormone (LH) levels of male rats. Methods: Sixty adult male Sprague Dawley rats were used in this study in four groups. Group A served as normal control, Group B received 0.3% lead acetate in drinking water, Group C and group D received supplementary 0.5 and 1 gm/Kg bodyweight of ginger respectively along with lead acetate in drinking water. Five rats from each group were sacrificed at the end of 2 nd , 4 th and 6 th weeks. Serum testosterone and LH levels were analysed using ELISA technique. Results: After co administration with different doses of ginger, serum testosterone level which was significantly decreased in lead treated group, showed a significant rise as compared to lead treated group. LH levels which had exhibited no significant change by lead treatment, after co administration with different doses of ginger, again showed no significant change. Conclusion: Oral administration of ginger ameliorated lead induced testicular toxicity in male rats by increasing serum testosterone level at all durations which might be a product of both its androgenic and antioxidant properties. Keywords: Lead toxicity, testosterone, luteinizing hormone, Zingiber officinale, male rats, antioxidant

Metal-ion susceptibility of oral bacterial species.

Abstract: Summary Aims: This study aimed to evaluate the effect of lead (Pb) on growth of bacterial species related to dental diseases in vitro. Methods and Results: The effects of lead acetate on representative species of the oral flora were examined at 0·1–10 mmol l−1 and compared with the effect of silver nitrate and ferrous sulfate. The minimal inhibitory concentration of lead acetate was between 0·15 and 5 mmol l−1 for the bacterial strains tested. The minimal bactericidal concentration of lead acetate for most oral species was detected in the range of 5–10 mmol l−1. Silver nitrate at a concentration of 1·25 mmol l−1 was sufficient to exhibit antibacterial activity against almost all bacteria tested. Ferrous sulfate had the lowest effect. Conclusions: The study indicated a general antimicrobial effect of lead on oral bacterial species in the range of 0·15–10 mmol l−1. The toxicity of silver nitrate was the highest, whereas that of ferrous sulfate was the lowest. Gram-positive species had a tendency to be less susceptible for metals than Gram-negatives. Significance and Impact of the Study: The study shows that it is possible that microbiological changes may occur in the dental plaque in children because of toxic exposure of environmental lead.

Effect of Glycine on Lead Mobilization, Lead-Induced Oxidative Stress, and Hepatic Toxicity in Rats

Abstract: The effectiveness of glycine in treating experimental lead intoxication was examined in rats. Male Wistar rats were exposed to 3 g/L lead acetate in drinking water for 5 weeks and treated thereafter with glycine (100 and 500 mg/kg, orally) once daily for 5 days or glycine (1000 mg/kg, orally) once daily for 28 days. The effect of these treatments on parameters indicative of oxidative stress (glutathione and malondialdehyde levels), the activity of blood 𝛿 -aminolevulinic acid dehydratase, and lead concentration in blood, liver, kidney, brain, and bone were investigated. Liver samples were observed for histopathological changes. Glycine was found to be effective in (1) increasing glutathione levels; (2) reducing malondialdehyde levels; (3) decreasing lead levels in bone with the highest dose. However, glycine had no effect on lead mobilization when 100 and 500 mg/kg glycine were administered. In microscopic examination, glycine showed a protective effect against lead intoxication.