[Obesity, malic enzyme and aging--an animal experiment study]

Area of Science:

• Biochemistry
• Physiology
• Endocrinology

Context:

• Investigates the impact of aging and experimentally induced obesity on malic enzyme activity in male Wistar rats.
• Obesity was induced in newborn rats using Na(+)-L-glutamate injections.
• Enzyme activity was assessed at 2, 6, and 18 months of age.

Purpose:

• To determine how age and obesity affect malic enzyme (EC 1.1.1.40) activity across various organs.
• To evaluate the glutamate-treated rat as a model for studying age-related diseases such as obesity and type II diabetes.

Summary:

• In control rats, malic enzyme activity peaked at 6 months in the heart, liver, fat pad, and skeletal muscle, declining by 18 months.
• Kidney activity decreased with age, while brain activity increased.
• Glutamate-induced obese rats exhibited doubled malic enzyme activity in the liver and fat tissue compared to controls across all ages.
• Clonidine treatment in obese rats reduced enzyme activity in liver and fat tissue, but it remained higher than in normal controls.

Impact:

• Provides insights into the metabolic changes associated with aging and obesity at the enzymatic level.
• Highlights the significant elevation of malic enzyme in lipogenic tissues of obese rats, suggesting altered lipid metabolism.
• Suggests the glutamate-induced obese rat model warrants further investigation for studying age-associated metabolic disorders.