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[Effects of manganese exposure on liver in rats]
Yanming Wu1, Dexing Zhang, Xinghong He
1Department of Basic Sciences, Guangdong Pharmaceutical College, Guangzhou 510006, China. yanmingjx@sina.com
Objective:
To observe effects of manganese on function and pathology of liver in rats.
Methods:
36 male SD rats were randomly divited into 3 groups, each group contained 12 rats. Solutions contained MnCl2 of 5.0 g/L and 0.5 g/L were respectively administrated to the high dose and low dose Mn-exposed groups consecutively by oral drinking for 60 days, while distilled water was given to the contal group. Fluorospectrophotometry was carried out to exame the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), as well as the protein level in liver plasmas. HE staining for the liver sections was applied to exam the pathological changes of liver in rats.
Results:
(1) In fluorospe-ctrophotometry, activities of ALT, AST, ALP in high and low dose Mn-exposed groups were significantly higher than those in control group in liver plasmas. In high dose Mn-exposed groups, ALT, AST, ALP was respectively (60.79 +/- 9.88), (49.77 +/- 8.36) and (49.43 +/- 8.88) U/ml, P < 0.01, in low dose Mn-exposed groups, ALT,AST,ALP was respectively (47.35 +/- 8.11), (37.31 +/- 6.77) and (32.34 +/- 4.53) U/ml (P < 0.05). Significant relationships between effects and dose were obvious in the above changes. No changes in PRO levels was found among 3 groups. (2) Pathologically in high dose and low dose Mn-exposed groups the hepatic lobules were injured in different levels. Mainly the arrangements of some hepatic cords became loose or disordered and liver cells were somewhat different in shape and apparent volume. Some hepatic cells appeared lipopexic and numerous granulocytic immersion occurred around the central vein.
Conclusion:
manganese exposure resulted in the poisonous effects on liver in rats.
Insights
Manganese exposure significantly elevated liver enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in rats. Pathological examination revealed liver tissue damage in manganese-exposed groups, indicating toxic effects.
Area of Science:
- Toxicology
- Hepatology
- Environmental Health
Context:
- Manganese is an essential trace element but can be toxic at elevated levels.
- Occupational and environmental exposure to manganese is a concern.
- Understanding the specific organ toxicity of manganese is crucial for risk assessment.
Purpose:
- To investigate the functional and pathological effects of manganese exposure on the liver in a rat model.
- To quantify changes in key liver enzymes and assess histological alterations.
Summary:
- Male Sprague-Dawley rats were exposed to two doses of manganese chloride (MnCl2) or distilled water for 60 days.
- Liver function was assessed by measuring serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) activities.
- Histopathological examination using Hematoxylin and Eosin (HE) staining evaluated liver tissue damage.
Impact:
- Results demonstrate a dose-dependent increase in liver enzymes (ALT, AST, ALP) in manganese-exposed rats compared to controls.
- Pathological findings indicated varying degrees of hepatic lobule injury, including disordered hepatic cords and cellular changes.
- This study confirms that manganese exposure induces toxic effects on the rat liver, highlighting potential risks to liver health.
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