Recording-2025-03-10T02:31:00.126Z

Beta Cells: Key components in controlling blood glucose levels.
Importance: Central focus of diabetes research since the 1980s, leading to the development of various drugs targeting beta cells.
Notable Drug: Ozempic is highlighted; developed from understanding beta cell function.

Alpha Cells Function: Secretion of glucagon, vital for raising blood glucose levels in response to hypoglycemia.
Comparison with Beta Cells: Less is known about alpha cells and their mechanisms despite their crucial role in glucose homeostasis.

Primary Goals of Lecture:
- Describe mechanisms regulating insulin secretion in pancreas.
- Discuss differences between type 1 and type 2 diabetes.
Types of Diabetes: Distinction between various diabetes forms; primary focus on type 1 and type 2 diabetes, including gestational diabetes.

Type 1 Diabetes:
- An autoimmune disease resulting in beta cell destruction.
- Characterized by lack of insulin production, causing severe fluctuations in blood glucose.
Type 2 Diabetes:
- A metabolic disease often related to insulin resistance, with functional beta cells still present.
Key Difference: Type 1 is autoimmune, while type 2 is related to metabolic dysfunction.

Fasting vs. Fed States:
- Insulin lowers blood glucose during fed state.
- Glucagon increases blood glucose during fasting state.
Understanding the Pancreas:
- Exocrine vs. Endocrine Functions: majority of pancreas secretes digestive enzymes (exocrine), while islets of Langerhans regulate glucose (endocrine).
Islets of Langerhans: Contain various cell types, primarily beta cells responsible for insulin secretion.

Islet Cell Composition: Predominantly beta cells, along with alpha cells and delta cells (somatostatin-secreting).
Blood Glucose Homeostasis: All cell types in islets work synergistically to regulate glucose levels.

Stimulus-Secretion Coupling: How beta cells detect and respond to glucose.
Mechanism:
1. Glucose Entry: Through GLUT2 transporter.
2. ATP Generation: Glucose metabolized in mitochondria to produce ATP.
3. KATP Channel Closure: Closure due to increased ATP levels alters membrane potential.
4. Depolarization: Results in opening of voltage-dependent calcium channels leading to calcium influx.
5. Insulin Granule Exocytosis: Rise in calcium triggers fusion and secretion of insulin granules.

Hormonal Interactions: Beta cells respond to glucose and hormones (e.g., GLP-1) which enhances insulin secretion.
GLP-1 Action: Derived from gut cells, augments insulin response but requires glucose for action.

Autoimmune Component: Beta cell destruction due to immune response against autoantigens.
Ketoacidosis: Often the first clinical presentation leading to diagnosis.
Early Warning Signs: Presence of autoantibodies indicating risk of disease.

Insulin Resistance: Characterized by ineffective insulin action in muscle and fat cells.
Genetic Factors: Over 200 genes linked to predisposition; beta cell dysfunction crucial for progression.
Complications: High blood glucose leads to long-term health complications like neuropathy, retinopathy, and cardiovascular disease.

Continuous Glucose Monitoring: Advancements in tracking glucose levels to manage diabetes effectively.
Ozempic: A GLP-1 receptor agonist that improves insulin secretion in type 2 diabetes and aids weight loss.

abetes: Knowledge of beta and alpha cell function critical for developing effective treatments.

Research Advances: Continuous exploration in understanding diabetes promotes better management strategies.