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Published on: May 15, 2019
Immobilization stress increases endogenous monoamine oxidase (MAO) inhibitor in rat liver
1Department of Analytical Chemistry, Ohu University School of Pharmaceutical Sciences, Koriyama, Fukushima 963-8611, Japan. t-obata@pha.ohu-u.ac.jp
Abstract:
Although the physiological role of endogenous monoamine oxidase (MAO) inhibitor still remains unclear, the present study examined whether or not immobilization stress (IMMO) induce MAO inhibitor. An endogenous inhibitor of MAO was separated by gel filtration from 105,000 g supernate in rat liver cytosol following IMMO. The molecular weight of this inhibitor was estimated to be 500-600 by gel filtration. This inhibitor was proved to be heat-stable resistant to protease treatment. IMMO for 2 h significantly decreased MAO. These results suggest that this inhibitor is induced by IMMO. MAO activity in rat liver might be regulated by the level of this inhibitor.
Insights
Immobilization stress (IMMO) in rats induces a heat-stable, protease-resistant monoamine oxidase (MAO) inhibitor in the liver. This stress-induced MAO inhibitor may regulate MAO activity.
Area of Science:
- Biochemistry
- Neuroscience
- Stress Physiology
Background:
- The physiological role of endogenous monoamine oxidase (MAO) inhibitors is not fully understood.
- Monoamine oxidase plays a crucial role in neurotransmitter metabolism.
Purpose of the Study:
- To investigate whether immobilization stress (IMMO) induces the production of an endogenous MAO inhibitor.
- To characterize the properties of the potential stress-induced MAO inhibitor.
Main Methods:
- Rat liver cytosol was fractionated using gel filtration after IMMO.
- MAO activity was measured.
- The inhibitor's molecular weight, heat stability, and resistance to protease treatment were assessed.
Main Results:
- An endogenous MAO inhibitor was isolated from rat liver cytosol following IMMO.
- The inhibitor has an estimated molecular weight of 500-600 Da.
- The inhibitor is heat-stable and resistant to protease treatment.
- IMMO for 2 hours significantly decreased MAO activity.
Conclusions:
- Immobilization stress induces the production of an endogenous MAO inhibitor in rat liver.
- This stress-induced MAO inhibitor may play a role in regulating MAO activity in the liver.
