Exploration of the establishment of manganese poisoning rat model and analysis of discriminant methods.

OBJECTIVE: We explored methods to establish an animal model of manganese poisoning and evaluate the feasibility of the determination method.

METHODS: Twenty-four specific pathogen-free male rats were randomly divided into four groups: control, low-dose (15.0 mg/kg), middle-dose (25.0 mg/kg), and high-dose (50.0 mg/kg). Intraperitoneal injection of MnCl2 ·H2 O was administered every 48 h for three months. Rats were tested for behavior, muscle tension, and with a balance beam experiment at the end of each month. Three months later, the rats were sacrificed and brain tyrosine hydroxylase (TH) expression levels were measured.

RESULTS: Rats in each group exhibited changes in behavior, muscle tone, and balance after exposure to manganese, and the scores of each test for the high-dose and middle-dose groups were statistically different from the low-dose and control groups. Finally, a rat model of manganese poisoning was identified with the TH expression less than 30% of the normal value. We find that the modeling success rate of the middle-dose and high-dose groups were 66.67% and 100%, respectively. In addition, there were negative correlations between the three assessment methods such as behavioral tests and TH expression levels.

CONCLUSIONS: Intraperitoneal injection of MnCl2 ·H2 O (25 mg/kg) can successfully establish a manganese poisoning rat model with low mortality rate. Muscle tension, balance beam, and behavioral tests can be used as preliminary determination methods for modeling.