AlCl3 Treatment Research Articles

Abstract 1157: Differential effects of aluminum exposure on epithelial and mesenchymal cells

Abstract Introduction: Aluminium [Al(III)] is the third most abundant element as well as the most abundant metal in the Earth's crust. The human population is exposed to Al throughout daily life; in drinking water, food, via application of antiperspirants, use of antacids and vaccination. However, aluminum exposure has been linked to a variety of pathological disorders like anemia, osteomalacia , hepatic disorder, and neurological disorder. In addition, studies report that aluminum levels are higher in tumors, including breast cancers than in surrounding normal tissues. This suggests that aluminum accumulation may provide some selective advantage to the tumor. Methods/Results:To determine how aluminum affects cells that reside in mammary tissue, we studied the in vitro effects of Al exposure on human mammary epithelial cells and mesenchymal cells. Cells used in our study included hTERT-immortalized human mammary epithelial cells (HMECs), the immortalized human mammary epithelial cell line (MCF10A), hTERT-immortalized reduction mammary fibroblasts (RMF/EG) and a dermal-derived human fibroblast cell line (MSU1.1). Using the MTT assay we found that AlCl3 and AlOH3 salts inhibit the growth of the mammary epithelial cells causing complete inhibition of proliferation at doses around 1mM and decreased proliferation was observed at doses as low as 12.8 uM. Surprisingly at these doses, Al salts caused dose-dependent increase in proliferation the mesenchymal cells. The proliferative effect of Al on mesenchymal cells was confirmed using clonogenic assay. Flow cytometric evaluation of cell cycle using PI/BrdU incorporation demonstrated that in MSU1.1 cells exposed to AlOH3 for 48 hrs, the percentage of cells in S phase of the cell cycle nearly doubled as compared to untreated cells (P <0.05). Similar results were seen with AlCl3 treatment of MSU1.1 and AlOH3/AlCl3 treatment of RMF/EG cells. Conclusions: These data indicate that while Al salts induce dose dependent cytotoxicity in human epithelial cell lines, they induce proliferation of mesenchymal cells. The tumor microenvironment, including a proliferative stroma, is known to facilitate mammary carcinogenesis. Our data suggest that Al accumulation could promote the development of a permissive microenvironment. We are currently seeking to determine the mechanism for the differential effect of Al in cells and whether this effect influences transformation or carcinogenesis. Citation Format: Manar A. AbdelMageed, Parthena Foltopoulou, Monica Betancur-Boissel, Elizabeth A. McNiel. Differential effects of aluminum exposure on epithelial and mesenchymal cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1157. doi:10.1158/1538-7445.AM2014-1157

Study of the effect of antidepressant drugs and donepezil on aluminum-induced memory impairment and biochemical alterations in rats

Alzheimer’s disease is the leading cause of dementia in the elderly. Depression is a common psychiatric disorder affecting individuals across life span and often arises in the context of pre-dementia, dementia, and Alzheimer’s disease. The present study aimed to investigate the effects of the antidepressant drugs clomipramine (14.2 and 56.9 μmol/kg), fluoxetine (14.5 and 57.8 μmol/kg), and sertraline (14.6 and 58.4 μmol/kg) compared with acetylcholinesterase inhibitor donepezil (12 μmol/kg) on oxidative stress, memory impairment, and depressant-like behavior in a model of Alzheimer’s disease induced by prolonged intraperitoneal administration of aluminum chloride (AlCl3) (10 mg/kg/day for 60 days) in rats. Results indicated that the latency to find the hidden platform in Morris water maze (MWM) test increased by 100 %, while the immobility duration in forced swimming test (FST) increased by 51 % in AlCl3-treated rats. The administration of AlCl3 resulted in increased brain malondialdehyde (MDA) by 58.6 % and nitric oxide (nitrite) concentrations by 71.7 %, while reduced glutathione (GSH) decreased by 35.6 % compared with the vehicle-treated group. Catalase and paraoxonase 1 (PON1) activities in the brain decreased by 41.8 and 18.3 %, respectively. Serum acetylcholinesterase (AChE) increased by 47.8 % and brain butyrylcholinesterase (BuChE) decreased by 23.1 % after AlCl3 treatment. In AlCl3-treated rats, memory performance in the MWM test improved following donepezil and the highest dose of clomipramine, fluoxetine, and sertraline. The immobility duration in the FST was decreased by sertraline. Significant decrease in brain MDA occurred after treatment with clomipramine, fluoxetine, and a lower dose of sertraline. Reduced glutathione level increased by donepezil, clomipramine, and 57.8 μmol/kg fluoxetine. The level of nitric oxide decreased by donepezil (42.6 %), clomipramine (45.0 and 62.9 %), fluoxetine (21.9 and 40.9 %), and 14.6 μmol/kg sertraline (28.7 %). Catalase activity was restored by donepezil, fluoxetine, and sertraline and markedly increased by 56.9 μmol/kg clomipramine. Paraoxonase 1 activity was increased by 14.2 μmol/kg clomipramine. BuChE activity was unaltered, but AChE activity was decreased by donepezil, clomipramine, and fluoxetine compared with the AlCl3 control group. AlCl3 resulted in neurodegeneration (gliosis), extensive dark neurons with corkscrew dendrites, and degeneration of some Purkinje cell. Following donepezil treatment, no dark neurons were observed, while increased granular cell layer was observed after the administration of a high dose of clomipramine, fluoxetine, or sertraline. The results suggested that in rats treated with AlCl3, (i) donepezil, sertraline, clomipramine, and fluoxetine improve memory performance; (ii) sertraline was particularly effective in improving depressive-like behavior in this model and might be of value in the treatment of depressive symptoms associated with Alzheimer’s disease; (iii) donepezil, clomipramine, and fluoxetine alleviated oxidative stress; and (iv) neurodegeneration in this model could be modulated by antidepressant drugs and donepezil.

Dual blockade of the A1 and A2A adenosine receptor prevents amyloid beta toxicity in neuroblastoma cells exposed to aluminum chloride

In a previous work we have shown that exposure to aluminum (Al) chloride (AlCl3) enhanced the neurotoxicity of the amyloid beta25-35 fragment (Abeta25-35) in neuroblastoma cells and affected the expression of Alzheimer's disease (AD)-related genes. Caffein, a compound endowed with beneficial effects against AD, exerts neuroprotection primarily through its antagonist activity on A2A adenosine receptors (A2AR), although it also inhibits A1Rs with similar potency. Still, studies on the specific involvement of these receptors in neuroprotection in a model of combined neurotoxicity (Abeta25-35+AlCl3) are missing. To address this issue, cultured SH-SY5Y cells exposed to Abeta25-35+AlCl3 were assessed for cell viability, morphology, intracellular ROS activity and expression of apoptosis-, stress- and AD-related proteins. To define the role of A1R and A2ARs, pretreatment with caffein, specific receptor antagonists (DPCPX or SCH58261) or siRNA-mediated gene knockdown were delivered. Results indicate that AlCl3 treatment exacerbated Abeta25-35 toxicity, increased ROS production, lipid peroxidation, β-secretase-1 (BACE1) and amyloid precursor protein (APP). Interestingly, SCH58261 successfully prevented toxicity associated to Abeta25-35 only, whereas pretreatment with both DPCPX and SCH58261 was required to fully avert Abeta25-35+AlCl3-induced damage, suggesting that A1Rs might also be critically involved in protection during combined toxicity. The effects of caffein were mimicked by both N-acetyl cysteine, an antioxidant, and desferrioxamine, likely acting through distinct mechanisms. Altogether, our data establish a novel protective function associated with A1R inhibition in the setting of combined Abeta25-35+AlCl3 neurotoxicity, and expand our current knowledge on the potential beneficial role of caffein to prevent AD progression in subjects environmentally exposed to aluminum.

Phosphorus Alleviates Aluminum Toxicity in Al-Sensitive Wheat Seedlings

The role of phosphorus (P) in the amelioration of aluminum (Al) toxicity to plants is still unclear. The aim of this study was to examine the amelioration of Al toxicity by P supply. The study involved growing Al-sensitive wheat seedlings for 13 days in an acidic soil [pH 4.5 in calcium chloride (CaCl2)] with increasing added rates of P (0, 20, 40, and 80 mg P kg−1 soil) and Al [0, 50, and 150 mg aluminum chloride (AlCl3) kg−1 soil]. The results indicated that the effects of Al toxicity in this soil could be fully alleviated by the application of P at 50 mg AlCl3 kg−1. The 150 mg kg−1 AlCl3 treatment significantly reduced root growth, but this was partially overcome by the 80 mg kg−1 P treatment. High P significantly reduced the concentration of Al in the apoplast, root, and shoot. It is possible that an insoluble Al-P complex forms in the soil and this decreases Al bound in apoplast as well as uptake into the roots. High P decreased the translocation of Al from root to shoot. This study also concluded that detoxification of Al3+ by P mainly occurs in soil but not within the plant tissue.

Water deficit and aluminum tolerance are associated with a high antioxidative enzyme capacity in Indica rice seedlings

Plant growth and productivity are greatly affected due to changes in the environmental conditions. In the present investigation, the interactive effects of two important abiotic stresses, i.e., water deficit and Al toxicity, were examined in the seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 (water deficit/Al sensitive) and Vandana (water deficit/Al tolerant). When 15 days grown seedlings were exposed to water deficit (created with 15 % polyethylene glycol 6000) or Al (1 mM AlCl3) treatment or both the treatments together for 48 h, the lengths of root/shoot, relative water content, and chlorophyll greatly declined in the seedlings of the sensitive cultivar, whereas in the tolerant seedlings, either little or insignificant decline in these parameters was observed due to the treatments. Seedlings subjected to water deficit or Al treatment alone or in combination showed increased intensity of the isoenzyme activity bands of superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX) in in-gel activity staining studies. Water deficit caused decrease in intensity of catalase (CAT) activity bands; however, when seedlings were exposed to AlCl3 alone or in combination with water deficit, the intensity of the CAT isoforms increased in both the rice cultivars. The level of expression of the activity bands of SOD, CAT, GPX, and APX was always higher in the seedlings of tolerant cv. Vandana compared to the sensitive cv. Malviya-36 under both controls as well as stress treatments. Higher intensity of isozymes representing higher activity levels of antioxidative enzymes in the rice seedlings and their further increase under water deficit, Al exposure, or in combination of both the stresses appears to serve as useful marker for specifying a combination of water deficit and Al tolerance in rice.

Physiological and transcriptional responses of broad bean (Vicia faba L.) leaves to aluminium stress

SummaryAluminium (Al) toxicity is the major factor-limiting crop productivity in acid soils. In the present study, physiological and transcriptional responses of broad bean leaves to Al stress were investigated. Malondialdehyde (MDA) content, H2O2 content and protein carbonyls (PC) level in leaves were increased after 100 μm AlCl3 stress treatment, whereas the total protein content was decreased, compared with the plants without Al treatment. Stomatal closure in leaves of broad bean was increased after Al stress, suggesting that the photosynthesis rate might be affected by Al stress. The relative citrate secretion in leaves was decreased after Al treatment for 24 h according to the 13C-NMR analysis, indicating that citrate in leaves might be transported to the root to chelate Al3+. To investigate the molecular mechanisms of Al toxicity in leaves of broad bean, a suppression subtractive hybridization (SSH) library was constructed to identify up-regulated genes: cDNA from leaves subjected to 12, 24, 48 and 72 h of 50 and 100 μm AlCl3 stress were used as testers and cDNA from leaves subjected to 0 μm AlCl3 treatment for the same lengths of time as above were used as a driver. The SSH analysis identified 156 non-redundant putative Al stress-responsive expressed sequence tags (ESTs) out of 960 clones. The ESTs were categorized into ten functional groups, which were involved in metabolism (0·21), protein synthesis and protein fate (0·10), photosynthesis and chloroplast structure (0·09), transporter (0·08), cell wall related (0·06), signal transduction (0·05), defence, stress and cell death (0·05), energy (0·03), transcription factor (0·03) and unknown proteins (0·30). The effect of Al treatment on expression of 15 selected genes was investigated by reverse transcription polymerase chain reaction (RT–PCR), confirming induction by Al stress. The results indicated that genes involved in organic acid metabolism, transport, photosynthesis and chloroplast structure, defence, stress and cell death might play important roles under Al stress.

Genome-wide identification, characterization and expression analysis of populusleucine-rich repeat receptor-like protein kinase genes

BackgroundLeucine-rich repeat receptor-like kinases (LRR-RLKs) comprise the largest group within the receptor-like kinase (RLK) superfamily in plants. This gene family plays critical and diverse roles in plant growth, development and stress response. Although the LRR-RLK families in Arabidopsis and rice have been previously analyzed, no comprehensive studies have been performed on this gene family in tree species.ResultsIn this work, 379 LRR-RLK genes were retrieved from the Populus trichocarpa genome and further grouped into 14 subfamilies based on their structural and sequence similarities. Approximately 82% (312 out of 379) of the PtLRR-RLK genes are located in segmental duplication blocks indicating the role of duplication process in the expansion of this gene family. The conservation and variation in motif composition and intron/exon arrangement among PtLRR-RLK subfamilies were analyzed to provide additional support for their phylogenetic relationship and more importantly to indicate the potential divergence in their functions. Expression profiling of PtLRR-RLKs showed that they were differentially expressed in different organs and tissues and some PtLRR-RLKs were specifically expressed in meristem tissues, which indicated their potential involvement in tissue development and differentiation. For most AtLRR-RLKs with defined functions, Populus homologues exhibiting similar expression patterns could be identified, which might indicate the functional conservation during evolution. Among 12 types of environmental cues analyzed by the genome-wide microarray data, PtLRR-RLKs showed specific responses to shoot organogenesis, wounding, low ammonium feeding, hypoxia and seasonal dormancy, but not to drought, re-watering after drought, flooding, AlCl3 treatment and bacteria or fungi treatments.ConclusionsThis study provides the first comprehensive genomic analysis of the Populus LRR-RLK gene family. Segmental duplication contributes significantly to the expansion of this gene family. Populus and Arabidopsis LRR-RLK homologues not only share similar genetic structures but also exhibit comparable expression patterns which point to the possible functional conservation of these LRR-RLKs in two model systems. Transcriptome profiling provides the first insight into the functional divergence among PtLRR-RLK gene subfamilies and suggests that they might take important roles in growth and adaptation of tree species.

The effect of poultry manure application rate and AlCl3 treatment on bacterial fecal indicators in runoff

Increasing costs associated with inorganic fertilizer have led to widespread use of broiler litter. Proper land application, typically limiting nutrient loss, is essential to protect surface water. This study was designed to evaluate litter-borne microbial runoff (heterotrophic plate count bacteria, staphylococci, Escherichia coli, enterococci, and Clostridium perfringens) while applying typical nutrient-control methods. Field studies were conducted in which plots with high and low litter rates, inorganic fertilizer, AlCl(3)-treated litter, and controls were rained on five times using a rain generator. Overall, microbial runoff from poultry litter applied plots was consistently greater (2-5 log(10) plot(-1)) than controls. No appreciable effect on microbial runoff was noted from variable litter application rate or AlCl(3) treatments, though rain event, not time, significantly affected runoff load. C. perfringens and staphylococci runoff were consistently associated with poultry litter application, during early rain events, while other indicators were unreliable. Large microbial runoff pulses were observed, ranging from 10(2) to 10(10) CFU plot(-1); however, only a small fraction of litter-borne microbes were recoverable in runoff. This study indicated that microbial runoff from litter-applied plots can be substantial, and that methods intended to reduce nutrient losses do not necessarily reduce microbial runoff.

Physiological and Biochemical Responses to Aluminum Stress in the Root of a Biodiesel Plant Jatropha curcas L.

We investigated J. curcas responses to aluminum stress, histochemically and biochemically. Histochemical stainings were observed to analysis aluminum accumulation, lipid peroxidation and the loss of plasma membrane integrity on the surface and tissue of the root apex. Enzymatic analysis was conducted to measure malate content in leaf, root and malate efflux in the medium. We used M. malabathricum as a comparison for Al-tolerance plant. J. curcas root elongation was inhibited by 0.4 mM AlCl3, while M. malabathricum root elongation was inhibited by 0.8 mM AlCl3 treatment. Inhibition of root elongation has high correlation with Al accumulation in the root apex, which caused lipid degradation and cell death. Generally, malate content in J. curcas leaf and root was higher than that in M. malabathricum. In the contrary malate efflux from the root into the medium was lower. J. curcas root has a different pattern compared to M. malabathricum in malate synthesis and malate secretion when treated with a different Al concentration. We categorized J. curcas acc IP3 as more sensitive to aluminum than M. malabathricum.

Reducing ammonia emissions and volatile fatty acids in poultry litter with liquid aluminum chloride

This study was a pen trial in which the effects of adding different rates of liquid aluminum chloride (AlCl3) on litter pH, total volatile fatty acids (VFAs), and ammonia (NH3) fluxes was evaluated. Liquid AlCl3 treatments used in this study were sprayed on the rice hull surface at rates of 100 g, 200 g, and 300 g liquid AlCl3/kg rice hulls; untreated rice hulls served as controls. Litter pH, total VFAs, and NH3 fluxes were all lowered (P< 0.05) by all of the liquid AlCl3 treatments compared with controls during certain times of the 5 week study. However, there were no significant differences among treatments on litter pH at the end of the study (from 3 to 5 weeks) or NH3 fluxes at beginning of the study (0 to 3 weeks). Total VFAs were reduced 16 %, 29 %, and 53 % by 100 g liquid AlCl3/kg rice hulls, 200 g liquid AlCl3/kg rice hulls, and 300 g liquid AlCl3/kg rice hulls, respectively. Liquid AlCl3additions reduced NH3 fluxes by 35 %, 57 % and 67 %, respectively, at the low, medium and high rates. In summary, these results indicate that adding liquid aluminum chloride to rice hulls would be a useful tool in reducing the negative environmental impact of poultry litter. It should be noted that the decreased VFA production and NH3 volatilization was chiefly associated with reduction in litter pH.

氯化铝和聚合氯化铝(PAC)在黄河水中的混凝效果与残留铝含量及组分

The coagulation performance of AlCl3 and polyaluminum chloride (PAC) during treatment of water from the Yellow River was investigated with different initial pH conditions and coagulant doses. Speciation of the residual aluminum was also studied. PAC showed superior coagulation performance to AlCl3, and it altered the initial pH slightly under alkaline conditions. For Yellow River water treatment with PAC and AlCl3, the optimum initial pH was 6.0 and the optimum coagulant dose was 15 mg/L (Al). Under these conditions, the removal of turbidity, UV254 and dissolved organic carbon was optimized. The organic material in the effluent after coagulation was mostly hydrophobic, and this material was removed better with higher coagulant doses and in neutral or weakly alkaline conditions. It was not easy for the Al from PAC to transfer to and remain in the effluent, and PAC’s residual aluminum ratio was lower than that of AlCl3. With a coagulant dose of 11-15 mg/L and initial pH of 8.0, there was little Al remaining in the water after treatment with either AlCl3 or PAC. The residual Al was mainly present as dissolved Al, and dissolved organically bound Al was the predominant species. Dissolved inorganically bound monomeric Al was the main component in dissolved monomeric Al. The residual Al concentration was effectively controlled using a coagulant dose of 10-15 mg/L and initial pH of 7.0-8.5. PAC treatment produced lower concentrations for several residual Al species, except for dissolved organically bound Al, than AlCl3 treatment. PAC could effectively reduce the concentration of dissolved Al and dissolved monomeric Al in water after treatment.

Behavior of aluminum adsorption on cell wall of pineapple root apices

Pineapple (Ananas comosus (L.) Merrill) is commonly grown in strongly acid soil, in which high aluminum (Al) concentration is often toxic to the roots of plants. The root apices of plants are most sensitive to Al toxicity. This paper is to evaluate the effect of Al on the growth of roots of four pineapple cultivars: Cayenne, Tainung No.6, Tainung No.13 and Tainung No.17 in Taiwan. The differences in the amount of callose and malondialdehyde (MDA) in root apices (1 cm in length) between Al-resistant and Al-sensitive pineapple treated with 0 and 300 µM AlCl3 were determined. The role that the cell wall of root apices plays in Al-resistant characteristics is also discussed. After treating with 300 µM AlCl3 in hydroponic solution (pH 4.5) for 72 h, the root elongation of Cayenne, Tainung No. 6, Tainung No. 13 and Tainung No. 17 was 115, 85, 93 and 73% of the values obtained compared to that without Al treatment, respectively. AlCl3 treatment did not increase callose and MDA contents for Cayenne, but caused significant increase for Tainung No.17. Upon exposure to Al, Al adsorption on cell walls of root apices increased with time and AlCl3 concentrations for Cayenne and Tainung No.17, but relatively greater in Tainung No.17. It reflects the fact that, Cayenne is Al-resistant and Tainung No.17 is Al-sensitive. When root apices were pretreated with 1 and 10 mM of malic acid, the Al adsorption of the cell walls of Cayenne’s root apex was lower by 18 and 31%, respectively, relative to the values obtained without the malic acid treatment. It indicates that root apex of Cayenne may secrete more malic acid that is capable of Al complexation, as well as reducing the Al binding to cell walls in order to better resist Al toxicity. Key words: Aluminum, pineapple, root apices, cell wall, adsorption.

Camel's Milk Protects Against Aluminum Chloride-Induced Normocytic Normocromic Anemia, Lipid Peroxidation and Oxidative Stress in Erythrocytes of White Albino Rats

Problem statement: Aluminum (Al) is an indifferent element from a toxicological point of view. In recent years, however, Al has been implicated in the pathogenesis of several clinical disorders. One of the most frequently described problem in aluminum toxicity is anemia. The present study was carried out to determine the effectiveness of Camel’s milk in alleviating the toxicity of aluminum chloride (AlCl3) on certain hematological parameters, lipid peroxidation and oxidative stress enzyme in the RBC’s of white albino rats. Approach: Ten rats per group were divided into three treatment groups: Group one were rats given normal saline and served as control group, group two were rats treated with 1 ml of AlCl3 (0.5 mg kg-1 body weight) and named AlCl3 treated rats, group 3 were rat treated with 1ml fresh camel’s milk 10 min before the administration of AlCl3 (0.5 mg kg-1 body weight) and named Camel’s milk and AlCl3 treated rats. Rats were orally administered their respective doses every day for 30 days. Evaluations were made for hematological parameters in the blood and for lipid peroxidation and oxidative stress enzymes activities in the RBC’s. Results: Results obtained showed that oral AlCl3 treatment caused a significant decrease (p<0.05) in total erythrocytes count, blood Hemoglobin (Hb), hematocrite (PCV) and Serum iron levels, where as the values of Mean Corpuscular Volume (MCV), Mean Hemoglobin Concentration (MHC), Mean Corpuscular Hemoglobin Concentration (MCHC) and Total Ion Binding Capacity (TIBC) didn’t change. Also oral administration of AlCl3 induced free radicals and as a result caused an increase the concentration of Thiobarbituric Acid Reactive Substances (TBARS) and decreased activities of Superoxide Dismutase (SOD) and Catalsae (CAT) in the RBCs homolysate. The oral administration of Camel’s milk before the administration of AlCl3, alleviated it’s toxic effect. Camel’s milk administration resulted in a significant increase (p<0.05) in the in total erythrocytes count, blood hemoglobin (Hb), hematocrite (PCV) and Serum iron with No change in the values of MCV, MHC, MCHC and TIBC when compared to AlCl3 treated rats. Camel’s milk reduced free radicals production and oxidative stress status in the RBC’s noticed by the significant decreased levels of TBARS and increased activities of SOD and CAT when compared to AlCl3 treated rats. Conclusion: our data proved that there is an alternation in the hematological parameters and antioxidant system in the red blood cells of rats administered aluminum chloride orally, whereas oral administration of Camel’s milk prior the administration of Aluminum chloride protects the red blood cell form toxic effect of aluminum.

Aluminum induces chromosome aberrations, micronuclei, and cell cycle dysfunction in root cells of Vicia faba

Aluminum (Al) exists naturally in air, water, and soil, and also in our diet. Al can be absorbed into the human body and accumulates in different tissues, which has been linked to the occurrence of Alzheimer's disease and various neurological disorders. By using Vicia cytogenetic tests, which are commonly used to monitor the genotoxicity of environmental pollutants, cytogenetic effects of aluminum (AlCl(3)) were investigated in this study. Present results showed that Al caused significant increases in the frequencies of micronuclei (MN) and anaphase chromosome aberrations in Vicia faba root tips exposed to Al over a concentration-tested range of 0.01-10 mM for 12 h. The frequency of micronucleated cells was higher in Al-treated groups at pH 4.5 than that at pH 5.8. Similarly, AlCl(3) treatment caused a decrease in the number of mitotic cells in a dose- and pH-dependent manner. The number of cells in each mitotic phase changed in Al-treated samples. Mitotic indices (MI) decreased with the increases of pycnotic cells. Our results demonstrate that aluminum chloride is a clear clastogenic/genotoxic and cytotoxic agent in Vicia root cells. The V. faba cytogenetic test could be used for the genotoxicity monitoring of aluminum water contamination.

Effects of Liquid Aluminum Chloride Additions to Poultry Litter on Broiler Performance, Ammonia Emissions, Soluble Phosphorus, Total Volatile Fatty Acids, and Nitrogen Contents of Litter

Recent studies have shown that the use of aluminum sulfate [alum, Al2(SO4)3·14H2 O] and aluminum chloride (AlCl3) additions to animal manures are more effective than other chemicals in reducing ammonia (NH3) emissions and P solubility. Although the use of Al2(SO4)3·14H2 O has been intensively used in the poultry industry for many years, no research has been conducted to evaluate the effect of liquid AlCl3 on these parameters. The objectives of this study were to determine the effects of applying liquid AlCl3 to poultry litter on 1) broiler performance, 2) NH3 fluxes, and 3) litter chemical characteristics, including soluble reactive P, total volatile fatty acids, and N content. Eight hundred broiler chicks were placed into 16 floor pens (50 birds/pen) in a single house for 6 wk. Liquid AlCl3 treatments were sprayed on the litter surface at rates of 100, 200, and 300 g of liquid AlCl3/kg of litter; un-treated litter served as controls. At the 2 lower rates, liquid AlCl3 treatments tended to improve weight gain and feed intake but had no effect on feed conversion or mortality, whereas the higher rate (300 g/kg of litter) had a negative effect on intake. Application of 100, 200, and 300 g of liquid AlCl3 reduced NH3 fluxes by 63, 76, and 76% during the 6-wk period, respectively, compared with the controls. Liquid AlCl3 additions reduced litter soluble reactive P contents by 24, 30, and 36%, respectively, at the low, medium, and high rates. Total volatile fatty acid contents (odor precursors) in litter were reduced by 20, 50, and 51%, respectively, with 100, 200, and 300 g of liquid AlCl3/kg of litter. Liquid AlCl3 additions increased total N, inorganic N, and plant available N contents in litter. These results indicate that liquid AlCl3 additions at the lower rates can provide significant positive environmental benefits to broiler operations.

Protective effect of ascorbic acid and glutathione on AlCl&lt;sub&gt;3&lt;/sub&gt;-inhibited growth of rice roots

The effect of AlCl3 on the antioxidant system of rice roots and the role of applied antioxidants ascorbic acid (AsA) and glutathione (GSH) in AlCl3-inhibited growth of rice roots were investigated. AlCl3 treatment resulted in a rapid inhibition of root growth but had no effect on lipid peroxidation and antioxidative enzyme activities in rice roots. AlCl3 treatment resulted in lower content of H2O2, AsA, and GSH than in controls. Exogenous AsA or GSH counteracted growth inhibition of rice roots induced by AlCl3. AlCl3 treatment increased syringaldazine peroxidase (SPOX) activities and lignin content in rice roots. Exogenous AsA or GSH prevented the decrease in H2O2 content and the increase in SPOX activities and lignin content in rice roots caused by AlCl3. Results suggest that lignification induced by low AsA or GSH content may explain the mechanism of Al-inhibited growth of rice roots.

Aluminum-inhibited root growth of rice seedlings is mediated through putrescine accumulation

The effects of AlCl3 on growth and polyamine levels of rice roots were investigated. When rice roots were treated with AlCl3, root growth was markedly inhibited. AlCl3 treatment resulted in a higher putrescine content and lower spermidine and spermine contents in rice roots. d-Argnine and α-methylornithine, inhibitors of putrescine biosynthesis, caused a reduced content of putrescine in rice roots under Al stress. AlCl3 treatment also resulted in a decrease in diamine oxidase activity in rice roots. The growth of rice roots in the presence of AlCl3 was recovered after the addition of d-arginine or α-methylornithine. The protective effect of d-arginine or α-methylornithine in counteracting AlCl3-inhibited growth of rice roots is unlikely caused by reduction of Al uptake. Furthermore, the effect of the growth recovery in AlCl3-treated rice roots by d-arginine or α-methylornithine was reversed by the addition of putrescine. Our results strongly suggest that putrescine accumulation is a factor causing growth inhibition of rice roots under Al tress. Evidence is also presented to show that lignification is responsible for putrescine- and AlCl3-inhibited growth of rice roots.

Effects of Dietary Aluminum from an Aluminum Water Treatment Residual on Bone Density and Bone Mineral Content of Feeder Lambs1

A 111-d experiment was conducted to determine if dietary Al provided by AlCl3 or water treatment residuals (WTR) at various levels (910 to 8,000 ppm) affected bone mineral content and bone density of growing sheep. Using a completely randomized design, 42 lambs (12 ewes and 30 wethers; 5 to 8 mo of age) were assigned to 1 of 6 treatments. Treatments were 1) 10% sand (control), 2) 9.7% sand and 0.3% AlCl3, 3) 7.5% sand and 2.5% WTR, 4) 5% sand and 5% WTR, 5) 0% sand and 10% WTR, and 6) 0% sand, 0% WTR, 2 times the quantities of the mineral and vitamin premix, and 1.29% dicalcium phosphate. Basal diets met all requirements and contained 0.25% P. The resulting concentrations of Al in the 6 treatment diets were 910, 2,000, 2,000, 4,000, 8,000, and 8,000 ppm, respectively. Radiographs of the left third metacarpal (MCIII) were obtained on d 28, 69, and 109 for estimation of bone density. Lambs were killed on d 111 and bone density of the left third metacarpal was determined by specific gravity procedures. Radiographic density was not affected by treatment. No differences in bone density were observed among treatments. Overall, results indicated that Al in various forms and levels fed to growing sheep provided adequate amounts of P (0.25%,) and that other required dietary nutrients had no effect on bone mineral content over a period of 79 d or on specific gravity calculations of bone density over 111 d.

Studies on Water Transport through the Sweet Cherry Fruit Surface: VIII. Effect of Selected Cations on Water Uptake and Fruit Cracking

Water uptake through the exocarp of intact sweet cherry [Prunus avium (L.)] fruit was determined gravimetrically in an immersion assay (25 °C). Fruit with sealed pedicel/fruit juncture were incubated in water during the first interval (0 to 0.75 hour) and in 10 mm salt solutions of selected cations during the second (0.75 to 1.5 hours) and third interval (1.5 to 2.25 hours) of an experiment. Rates of water uptake (F) were calculated for first, second and third intervals (FI, FII and FIII, respectively) and salt effects indexed by the ratios FII/FI and FIII/FI. AgNO3 (FII/FI = 0.65), NaCl (0.70), BaCl2 (0.67), CdCl2 (0.69), CuCl2 (0.42), HgCl2 (0.58), and SrCl2 (0.69), and the salts of trivalent cations AlCl3 (0.50), EuCl3 (0.58), and FeCl3 (0.49), significantly decreased water uptake into mature `Sam' fruit as compared to the water control (0.87). KCl (0.82), NH4Cl (0.85), CaCl2 (0.75), MgCl2 (0.88), MnCl2 (0.81), and ZnCl2 (0.72) had no effect, LiCl (1.00) increased uptake. Similar data were obtained for FIII/FI. The effect of FeCl3 on water uptake was independent of the presence of CaCl2, AlCl3, or CuCl2, as sequential or simultaneous treatment with these salts reduced water uptake to the same extent as with FeCl3 alone. Increasing FeCl3 concentration up to 1 mm decreased uptake, higher concentrations had no further effect. FeCl3 and CaCl2 to a smaller extent decreased water uptake in developing `Regina' sweet cherry fruit (55 to 91 days after full bloom). FeCl3 had no significant effect on water uptake along the pedicel/fruit juncture, but markedly reduced uptake through the exocarp of all cultivars investigated (`Burlat', `Early Rivers', `Hedelfinger', `Knauffs', `Regina', `Sam', `Summit', and `Van'). Effects of CaCl2 on water uptake were limited to `Burlat', `Early Rivers', and `Hedelfinger'. CaCl2 and FeCl3 both decreased fruit cracking, but FeCl3 was more effective. The mode of action of mineral salts in decreasing water uptake and fruit cracking and their potential for field use are discussed.

The Effects of AlCl3Additions on Rhizosphere Soil and Fine Root Chemistry of Sugar Maple (Acer Saccharum)

Increased Al mobilization and Ca and Mg leaching have been linked to nutritional imbalances in sugar maple across the northeastern US and Canada. The susceptibility of sugar maple fine roots to Al stress is poorly understood, in part because roots respond to Al stress by altering the chemistry of the rhizosphere. AlCl3 was applied to plots of sugar maple at the Hubbard Brook Experimental Forest, NH. After two years of treatment, we sampled fine roots of sugar maple, rhizosphere soil, and bulk soil in the Oa horizon and the upper 10 cm of the mineral soil. AlCl3 treatments resulted in significantly less Ca (21%) and Mg (30%) in fine roots from the organic horizon, but had no significant effect on fine root Al. Fine root (Ca+Mg):Al ratios were 42% lower in AlCl3 plots than in controls, though most roots had ratios above critical toxicity thresholds developed for hydroponically grown sugar maple seedlings. In the mineral horizon, roots differed only in Mg concentration, which was 22% lower in AlCl3 plots. In the AlCl3 treated plots, rhizosphere soil in the organic horizon had 47% greater Al and 29% less Mg than in controls. Combining data from both treatments we found significantly less Al and organically bound Al in rhizosphere soil than in bulk soil, possibly due to leaching of Al from the rhizosphere by organic acids released by roots. These results suggest that increased mobilization of Al in soil lowers (Ca+Mg):Al ratios in sugar maple fine roots, though roots may minimize Al stress by leaching Al from the rhizosphere.