Annals of Occupational and Environmental Medicine

Original Article

The Brain Pathology on Recovery of Brain MRI after Manganese Administration in Rats: Ji Hyeon Jung, Jung Il Kim, Se Young Kim, Min Ho Jung, Soon Sub Choi, Soo Jin Kim, Young Jin Park, Kap Yeol Jung; Korean Journal of Occupational and Environmental Medicine 2010;22(4):371-377. Published online December 31, 2010; DOI: https://doi.org/10.35371/kjoem.2010.22.4.371

Abstract PDF: OBJECTIVES
This study was carried out to investigate the effect on manganese on the brain of Sprague-Dawley rats, with particular focus on changes to anatomical pathology when brain MRI was recovered after manganese administration.
METHODS
There were 15 rats divided into 3 groups of 5 based on dose of manganese: control group, low dose group (10 mg/kg), and high dose group (40 mg/kg). Each dosing group received an injection of normal saline and manganese via the tail vein once a week for 4 weeks. And then, the rats were observed for 12 weeks after stopping manganese administration. Next, each rat underwent a brain MRI and then each was sacrificed. After the rats were killed, the concentrations of blood manganese were measured, and pathologic examinations of the brain were performed.
RESULTS
The signal intensity of basal ganglia on T1-weighted imaging of brain MRI did not differ between dosing groups. However, the ratio of neuron/glial cell in the basal ganglia was decreased in the low- and high-dose groups compared to the control group.
CONCLUSIONS
This study showed that the damage of neuron in basal ganglia might be permanent after signal intensity of basal ganglia on T1-weighted imaging of brain MRI was recovered.

Original Article

The Change of Brain MRI and Pathology According to the Administered Dose of Manganese in Rats: Jae Myeong Lee, Jung Il Kim, Yoon Kou Kim, Min Ho Jung, Soon Sub Choi, Dae Chul Kim, Kap Yeol Jung; Korean Journal of Occupational and Environmental Medicine 2009;21(2):184-191. Published online June 30, 2009; DOI: https://doi.org/10.35371/kjoem.2009.21.2.184

Abstract PDF: OBJECTIVES
This study was carried out to investigate the effect of manganese on the brains of rats, and chronic exposure to manganese is known to induce Parkinsonism in human.
METHODS
The rats were divided into three groups: the first group was a control group that was administrated normal saline, and the second group was subdivided into the low dose group (10 mg/kg) and the high dose group (40 mg/kg) according to the administered dose of manganese. The rats of each group received an injection of normal saline and manganese via a tail vein once a week for 4 weeks. The rats were sacraficed at 4 weeks after the first adminstration of manganese. Brain MR imaging was performed before the rats were killed. After the rats were killed, the concentration of blood manganese was measured, and pathologic examination of the brain was performed in all the groups.
RESULTS
The concentration of blood manganese was increased proportionally to the administered dose. The signal intensity of the basal ganglia on the T1-weighted imaging of brain MRI was increased in accordance with the administered dose. The ratio of neuron/glial cells in the basal ganglia was decreased in the experiment group as compared to that of the control group.
CONCLUSIONS
This study showed that the signal intensity and the damage of neurons in basal ganglia were increased according to the administered dose of manganese in rats.

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