Mechanisms of aluminium neurotoxicity in oxidative stress-induced ...
Mechanisms of aluminium neurotoxicity in oxidative stress-induced ... Mechanisms of aluminium neurotoxicity in oxidative stress-induced ...
CHAPTER 2 experimental period of four weeks. Aluminium dosage was adjusted according to the animal‟s body weight just before experiment. All rats received a standard diet (A04, Panlab, Barcelona, Spain) and the corresponding drinking (saline or aluminium salt+citric acid) ad libitum. Body weight and fluid intake were measured three times a week to adjust the doses in order to achieve a constant aluminium and citric acid intake. Brain samples 108 After treatment, animals were sacrificed by decapitation and brains quickly excised. Regional brain segments [cerebellum (CE), ventral midbrain (VM), cortex (CO), hippocampus (H), striatum (ST)] were rapidly dissected out on ice plate, according to Paxinos and Watson (2007). Weighed brain regions were stored at –40°C until trace element analysis. Electrothermal atomic absorption spectrometry (ETAAS) The samples were homogenised and digested with nitric acid (HNO3) and H2O2, using microwave energy. A portion of 500 mg of sample was weighed into a digestion vessel and 2 mL of HNO3 were added. Afterwards, vessels were introduced into the microwave oven at 100 W during 12 min. Then, 1 mL of H2O2 was added into digestion vessel and introduced into the microwave oven during 10 min at 300 W. Subsequently, the sample was adjusted to its final volume (5 mL) by addition of ultrapure water. A portion of 20 µL of the digested sample was introduced into the graphite furnace tube for its analysis by ETAAS. Measurements were performed using an atomic absorption spectrometer Model 1100 B (Perkin-Elmer, Norwalk, CT, USA), equipped with an HGA-700 graphite furnace atomizer and AS-70 autosampler. A hollow cathode lamp operating at 25 mA, which provided a 309 nm line with a spectral bandwidth of 0.7 nm, was used. Deuterium background correction and pyrolytic graphite coated tubes with L´vov platforms were employed. All measurements made during this study used integrated absorbance with an integration time of 5 s. The mineralization and
CHAPTER 2 atomization used were 1,500 and 2,800 ºC respectively (Table 1). The volume injected was 20 µL. Each sample was digested by triplicate and measured by duplicate. Aluminium concentrations in samples were calculated using a standard addition method in an analytical range of 0-20 µg/L. The limit of detection was 0.12 µg/g. The accuracy of the method was investigated using the Reference Material DORM-2 with a certificated aluminium concentration of 10.9±1.7 µg/g, being the aluminium concentration obtained 11.4±2.2 µg/g. Reagents for aluminium determination were of the highest available purity in order to avoid any risk of sample contamination. All glassware was washed and kept in 10% (v/v) HNO3 for at least 48 hours and then rinsed with ultrapure water (Milli-RiOs/Q-A10). Statistical analysis Results were expressed as the mean ± SD. Statistical differences were tested using one-way ANOVA followed by Bonferroni‟s test for multiple comparisons. The accepted level of statistical significance was p < 0.05. All statistical procedures were carried out using the Statgraphics Plus 5.0 statistical package (Manugistics, Rockville, MD, USA). 109
- Page 81 and 82: INTRODUCTION and antiperspirants co
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- Page 93 and 94: INTRODUCTION mobilization of Ca 2+
- Page 95: Aluminium impairs neurotransmission
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- Page 152 and 153: CHAPTER 3 RESULTS In vivo effects o
- Page 154 and 155: CHAPTER 3 Effects of aluminium admi
- Page 156 and 157: CHAPTER 3 DISCUSSION 132 Aluminium
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- Page 162 and 163: CHAPTER 3 Fig. 1 Levels of TBARS (A
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- Page 166 and 167: CHAPTER 3 Fig. 3 Microphotographs s
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CHAPTER 2<br />
atomization used were 1,500 and 2,800 ºC respectively (Table 1). The volume <strong>in</strong>jected<br />
was 20 µL. Each sample was digested by triplicate and measured by duplicate.<br />
Alum<strong>in</strong>ium concentrations <strong>in</strong> samples were calculated us<strong>in</strong>g a standard addition method<br />
<strong>in</strong> an analytical range <strong>of</strong> 0-20 µg/L. The limit <strong>of</strong> detection was 0.12 µg/g. The accuracy<br />
<strong>of</strong> the method was <strong>in</strong>vestigated us<strong>in</strong>g the Reference Material DORM-2 with a<br />
certificated <strong>alum<strong>in</strong>ium</strong> concentration <strong>of</strong> 10.9±1.7 µg/g, be<strong>in</strong>g the <strong>alum<strong>in</strong>ium</strong><br />
concentration obta<strong>in</strong>ed 11.4±2.2 µg/g. Reagents for <strong>alum<strong>in</strong>ium</strong> determ<strong>in</strong>ation were <strong>of</strong><br />
the highest available purity <strong>in</strong> order to avoid any risk <strong>of</strong> sample contam<strong>in</strong>ation. All<br />
glassware was washed and kept <strong>in</strong> 10% (v/v) HNO3 for at least 48 hours and then r<strong>in</strong>sed<br />
with ultrapure water (Milli-RiOs/Q-A10).<br />
Statistical analysis<br />
Results were expressed as the mean ± SD. Statistical differences were tested us<strong>in</strong>g<br />
one-way ANOVA followed by Bonferroni‟s test for multiple comparisons. The<br />
accepted level <strong>of</strong> statistical significance was p < 0.05. All statistical procedures were<br />
carried out us<strong>in</strong>g the Statgraphics Plus 5.0 statistical package (Manugistics, Rockville,<br />
MD, USA).<br />
109
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