| Fluoride is one of the essential trace elements in living organisms. However, excessive fluoride releases free radicals, causes oxidative stress and leads to chronic fluorosis. During tissue damage, apoptosis is possibly one of the important mechanisms involved. Studies have revealed that excessive fluoride ingestion also affects liver function, particularly detoxification and metabolism.Calcium is pretty important for the health of the body, calcium constitute teeth and bones of the body calcium content accounted for the vast majority, form the basic skeleton, supporting the entire body.Also, Calcium is an important intracellular messenger molecule involved in regulating the body’s various biological effects. Low dietary calcium may have a synergistic effect with fluoride exposure, while high dietary calcium fluoride could alleviate the poisoning causing by fluorosis. So far, studies of relationship between fluorosis and dietary calcium has also been reported, but the effect and mechanism of dietary calcium fluoride exposure induced offspring of some physiological function is unknown, especially the impact of dietary calcium caused by fluoride exposure to the target organ of the liver rarely reported. In that case, on the basis of preliminary studies, this study choose the liver as the observation point, designed to investigate the appropriate amount of dietary calcium and its molecular mechanism of intervention-induced with liver damage in offspring exposed to fluoride, to provide basic information for the prevention and treatment for endemic fluorosis.Methods:In this study,, we selected 50 early weaning SD male rats for breeding, and 100 female rats, every rat’s weight is about 80 g. After one week’s adaptation were randomly divided into five groups.Control group (Control) drank tap water, and ate normal diet (calcium content of 0.79%); fluoride group (F) drank 100 mg/L NaF solution, and ate normal diet; low calcium group (LCa) drank tap water, and ate low calcium diet (calcium content of 0.063%); low calcium fluoride group (F+LCa) drank 100 mg/L NaF solution, and ate low calcium diet; high calcium fluoride group (F+HCa) drank 100 mg/L NaF solution, and ate high calcium diet (calcium content of 7%). Male rats drank tap water, and ate standard diet (fluorine content<0.2 mg/kg, calcium content of 7-10 g/kg).Feed rats for three months, and during the experiment, keep feeding room ventilation, room temperature about 25 ℃, humidity between 50% to 70%, with sterile clean wood shavings for bedding, every three days have a change and clean squirrels, and then mated for 1:1, taking 14 and 28 days rats for experimental, determined the pathological and ultrastructural changes of liver. The apoptosis, activities of GSH-Px, SOD, the level of MDA, the expression levels of Caspase12 in liver were also determined.Results:1.related index detection of liver function in the blood14 days female young mice:Compared with control group,the ALT activity of fluorine group and low calcium group, low calcium fluoride group and high calcium fluoride group had no significant change, but the low calcium group and low calcium fluoride group were decreased obviously in the blood, high calcium fluoride group was increased significantly; Compared with the fluoride group, the ALT activity of low calcium group and low calcium fluoride group were slightly lower,high calcium fluoride group was significantly elevated in the blood. Compared with control group,the fluorine group and low calcium group, low calcium fluoride group and high calcium fluoride group had no significant change in activity ofALP, Compared with the fluoride group, low calcium, low calcium fluoride group and high calcium fluoride group had no significant change in ALP activity. Compared with control group, the AST activity of fluorine group and low calcium group, low calcium fluoride group and high calcium fluoride group had no significant change, but the low calcium fluoride group was decreased obviously in the blood, the high calcium fluoride group was significantly elevated in the blood; Compared with fluoride group,the AST activity of low calcium group, low calcium fluoride group and high calcium fluoride group had no significant change, but the low calcium fluoride group was decreased obviously in the blood, the high calcium fluoride group was significantly elevated in the blood at the same time.14 days male young mice:Compared with the control group, the fluoride group, low calcium group, low calcium and calcium fluoride group ALT activity did not change significantly, but the low calcium fluoride was significantly lower; Compared with the fluoride group, low calcium group, low calcium and calcium fluoride group ALT activity did not change significantly, but low calcium and calcium fluoride group was significantly lower. Compared with the control group, the fluoride group, low calcium group and calcium fluoride group ALP activity did not change significantly, but low calcium fluoride group ALP activity increased significantly (p<0.05); Compared with the fluoride group, low calcium group, low calcium and calcium fluoride group ALP activity was not significantly changed. Compared with the control group, the fluoride group, low calcium group, low calcium and calcium fluoride group AST activity did not change significantly; Compared with the dye fluoride group, low calcium group, low calcium and calcium fluoride group AST activity do not change significantly.28 days female young mice:Compared with control group,the ALT activity of low calcium group and the fluoride group had no significant change, but has a tendency to rise, high calcium fluoride group and low calcium fluoride group had no significantly change, but has a tendency to decline; Compared with the fluoride group, the ALT activity of the low calcium group had no significant chang, while low calcium fluoride group and high calcium fluoride group were decreased significantly (p<0.05). Compared with control group, the fluoride group had no significantly change in the activity of ALP, high calcium fluoride group, low calcium fluoride group and low calcium group were increased significantly (p<0.05), and had a increasing trend; Compared with the fluoride group, low calcium, low calcium fluoride group and high calcium fluoride group significantly increased the activity of ALP (p<0.05). Compared with the control group,the AST activity of high calcium fluoride group and low calcium fluoride group had no significant change, but had a tendency to rise, the fluorine group and low calcium group were significantly higher (p<0.05); Compared with the fluoride group, the AST activity of low calcium, low calcium fluoride group and high calcium fluoride group had no significantly change.28 days male young mice:Compared with the control group, the low calcium group,calcium fluoride group ALT activity did not change significantly, low calcium fluoride group reduced significantly (p<0.05); Compared with the fluoride group, low calcium group and calcium fluoride group ALT activity did not change significantly, low calcium fluoride group reduced significantly (p<0.05). Compared with the control group, the activity of ALP in fluoride group did not change significantly, calcium fluoride group, low calcium group and low calcium fluoride group ALP activity increased significantly (p<0.05), and there was an increasing trend; Compared with the fluoride group, calcium fluoride group, low calcium group and low calcium fluoride group ALP activity was significantly increased (p<0.05). Compared with the control group, the fluoride group AST activity did not change significantly, low calcium group, low calcium and calcium fluoride group were significantly higher (p<0.05), and there was an increasing trend; Compared with the fluoride group, low calcium group, low calcium and calcium fluoride group AST activity did not change significantly.2.liver tissue biochemical index14 days femle young mice:Compared with the control group, the content of MDA significantly increased in the low calcium fluoride group and high calcium fluoride group (p<0.05),and GSH-PX activity decreased clearly in the low caldum fluoride group,and SOD activity decreased significantly in the low calcium fluoride group (p<0.05).Compared with the fluoride group,the content of MDA significantly increased in the low calcium fluoride group (p<0.05) and SOD activity decreased significantly in the low calcium fluoride group (p<0.05).14 days male young mice: Compared with the control group, the content of MDA increased in the other groups,and GSH-PX activity decreased significantly in the low calcium group and low calcium fluoride group,and SOD activity decreased significantly in the low calcium fluoride group (p<0.05). Compared with the fluoride group, the content of MDA significantly increased in the low calcium fluoride group (p<0.05).28 days female young mice:Compared with the control group, the content of MDA significantly increased in the fluoride group and low calcium fluoride group (p<0.05),and activity of GSH-PX and SOD decreased clearly in the other groups. Compared with the fluoride group, the content of MDA significantly decreased in the low calcium group and high calcium fluoride group (p<0.05).28 days male young mice:Compared with the control group, the content of MDA significantly increased in the low calcium fluoride group and high calcium fluoride group (p<0.05), and activity of GSH-PX and SOD decreased clearly in the other groups. Compared with the fluoride group, the content of MDA significantly increased in the low calcium fluoride group and high calcium fluoride group (p<0.05)3.liver tissue Bcl-2 protein express level14 days female young mice:Compared with the control group,the level of Bcl-2 decreased in the fluoride group and low calcium group and high calcium fluoride group, the level of Bcl-2 decreased significantly in the low calcium fluoride group (p<0.05). Compared with the fluoride group, the level of Bcl-2 decreased significantly in the low calcium fluoride group (p<0.05).14 days male young mice: Compared with the control group, the level of Bcl-2 decreased significantly in the low calcium fluoride group (p<0.05). Compared with the fluoride group, the level of Bcl-2 decreased significantly in the low calcium fluoride group (p<0.05).28 days female and young mice:Compared with the control group,the level of Bcl-2 decreased significantly in the low calcium fluoride group (p<0.05) and the level of Bcl-2 decreased in the fluoride group and low calcium group and high calcium fluoride group. Compared with the fluoride group, the level of Bcl-2 decreased significantly in the low calcium fluoride group (p<0.05)4.1iver tissue Caspasel2 protein express level14 days female young mice:Compared with the control group,the level of Caspase12 increased significantly in the fluoride group,and low calcium fluoride group and high calcium fluoride group (p<0.05). Compared with the fluoride group, the level of Caspasel2 decreased significantly in the low calcium group and high calcium fluoride group (p<0.05).14 days male young mice:Compared with the control group, the level of Caspase12 increased significantly in the high calcium fluoride group (p<0.05),and the level of Caspase12 increased significantly extremely in the fluoride group,and low calcium fluoride group (p<0.01). Compared with the fluoride group, the level of Caspase12 decreased significantly in the low calcium group and high calcium fluoride group (p<0.05).28 days female young mice Compared with the control group,the level of Caspase12 increased significantly in the high calcium fluoride group (p<0.05) and the level of Caspase12 increased significantly extremely in the fluoride group,and low calcium fluoride group (p<0.01). Compared with the fluoride group, the level of Caspase12 decreased significantly in the high calcium fluoride group (p<0.05) and the level of Caspase12 decreased significantly extremely in the low calcium group (p<).28 days male young mice: Compared with the control group, the level of Caspasel2 increased significantly in the low calcium group (p<<0.05) and the level of Caspasel2 increased significantly extremely in the fluoride group,and low calcium fluoride group and high calcium fluoride group (p<0.01). Compared with the fluoride0.01 group, the level of Caspase12 decreased significantly in the high calcium fluoride group (p<0.05) and the level of Caspase12 decreased significantly extremely in the low calcium group (p<0.01)Conclusion:Fluorosis of drinking water can make excessive fluorine penetrate t he placental barrier and accumulate in offsprings. The mechanism of Fluorosis-Induce d Liver Injury may be that the exposure of the fluoride leads to Oxidative Stress of liv er tissue, suppression of antioxidant system and increase of lipid peroxidation, then in creases the expression of apoptosis pathway Caspasel2, leads to enhance the apoptosi s of liver cells, eventually causes liver damage. Fluorosis is timeliness, and males are more sensitive to it. Low dietary calcium can increase the symptoms of the fluorosis which shows synergistic effect between the low calcium and dye fluoride, to some de gree, high calcium can alleviate the symptoms of fluorosis. |
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