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Study of In Vivo Glucose Metabolism in High-fat Diet-fed Mice Using Oral Glucose Tolerance Test OGTT and Insulin Tolerance Test ITT
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Central IGF1 improves glucose tolerance and insulin sensitivity in mice
Hao Hong1, Zhen-Zhong Cui2, Lu Zhu2
1Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, P. R. China.
Nutrition & Diabetes
|December 21, 2017
Summary
Central Insulin-like Growth Factor 1 (IGF1) plays a crucial role in regulating appetite, glucose tolerance, and insulin sensitivity. This study demonstrates its significant impact on metabolic functions.
Area of Science:
- Endocrinology
- Neuroscience
- Metabolism
Background:
- Insulin-like growth factor 1 (IGF1) is vital for growth and metabolism.
- The role of central IGF1 in the brain's metabolic regulation is not fully understood.
- Previous observations linked increased hypothalamic IGF1 to obesity in specific mouse models.
Purpose of the Study:
- To investigate the metabolic functions regulated by IGF1 within the central nervous system (CNS).
- To elucidate the mechanisms by which central IGF1 influences appetite and metabolic homeostasis.
Main Methods:
- Administered IGF1 via intracerebroventricular (ICV) injection in mice.
- Overexpressed central IGF1 using adeno-associated virus (AAV) vectors.
- Inhibited central IGF1 activity using an anti-IGF1 antibody via ICV injection.
Main Results:
- Central IGF1 overexpression increased appetite and improved glucose tolerance and insulin sensitivity.
- Hypothalamic Pomc (pro-opiomelanocortin) levels were decreased.
- UCP1 (uncoupling protein 1) expression in brown adipose tissue was elevated.
Conclusions:
- Central IGF1 is a key regulator of critical metabolic functions, including appetite and glucose homeostasis.
- This study provides the first evidence for the direct role of central IGF1 in modulating these metabolic parameters.
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