Related Experiment Video
Updated: Jun 20, 2026
12:32
High-resolution Respirometry to Measure Mitochondrial Function of Intact Beta Cells in the Presence of Natural Compounds
Published on: January 23, 2018
[High glucose impairs mitochondrial respiratory chain function in pancreatic beta cells]
Zhan Lin1, Yao-Ming Xue, Jian-Ping Sha
1Department of Endocrinology and Metabolism, Nanfang Hospital, Southern Medical University, Guangzhou, China. linzhanok@163.com
Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University
|September 4, 2009
Summary
High glucose impairs mitochondrial respiratory chain function and insulin secretion in pancreatic beta cells. N-acetyl-L-cysteine (NAC) partially protects against these high glucose-induced damages, suggesting a role for oxidative stress.
Area of Science:
- Cell Biology
- Mitochondrial Biology
- Metabolic Research
Context:
- Pancreatic beta cells are crucial for insulin production.
- High glucose levels are implicated in diabetes pathogenesis.
- Mitochondrial dysfunction is increasingly recognized in metabolic diseases.
Purpose:
- To investigate the impact of high glucose on mitochondrial respiratory chain function in INS-1 cells.
- To assess the protective effect of N-acetyl-L-cysteine (NAC) against high glucose-induced cellular damage.
Summary:
- High glucose significantly reduced the activity of respiratory chain enzyme complexes I and III, as well as ATP and insulin levels in INS-1 cells.
- N-acetyl-L-cysteine (NAC) partially reversed these inhibitory effects, indicating a protective role against oxidative stress.
Impact:
- Reveals a direct link between impaired mitochondrial respiratory chain function and reduced insulin secretion under high glucose conditions.
- Highlights the potential therapeutic role of antioxidants like NAC in mitigating high glucose-induced pancreatic beta cell dysfunction.
Related Concept Videos
01:24Type II Diabetes II: Pathophysiology
PathophysiologyType 2 diabetes mellitus (T2DM ) is a chronic metabolic disorder characterized by insulin resistance and progressive pancreatic β-cell dysfunction, leading to impaired glucose homeostasis. It results from interactions among genetic predisposition, environmental factors, and metabolic stressors, such as overnutrition and a sedentary lifestyle.Insulin Resistance and Glucose DysregulationEarly T2DM involves insulin resistance in skeletal muscle, adipose tissue, and the liver.
01:27Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are co-secreted in...
Insulin and C-peptide are co-secreted in...
01:16Hormones Regulating Blood Glucose
Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
In addition to accelerating glucose uptake and utilization, insulin has...
01:36Carbohydrate Metabolism
Carbohydrates are polymers composed of molecules containing atoms of carbon, hydrogen and oxygen. One gram of carbohydrate can provide four kilo-calories of energy, which makes it the most efficient instant energy source.
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
Starch accounts for approximately 60% of the carbohydrates consumed by humans. Since amylase enzymes cannot function in the stomach's acidic environment, starch can only be digested in the mouth and small intestine. Simple sugars are found naturally in milk and fruits in the...
01:20Pathophysiology of Diabetes
Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia. The four categories of diabetes are type 1 diabetes, type 2 diabetes, other specific types of diabetes, and gestational diabetes.
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...
Type 1 diabetes is characterized by autoimmune-mediated destruction of pancreatic β cells, with environmental factors potentially triggering this process in genetically susceptible individuals. Despite many not having a family history, certain genes increase susceptibility, suggesting a...
01:05Insulin Secretory Vesicles
Insulin secretory vesicles release insulin to stimulate blood glucose uptake and regulate carbohydrate metabolism. When the blood glucose levels increase, glucose enters the pancreatic β-islet cells through glucose transporters. Once inside, glucose is metabolized through glycolysis, the citric acid cycle, and the electron transport chain, producing ATP. This increase in ATP concentration closes ATP-sensitive potassium channels, leading to depolarization of the membrane and the opening of...