GLUCAGON Presented By Daniel Vakili. Familiar Analogy.
-
Upload
thomas-harper -
Category
Documents
-
view
218 -
download
0
Transcript of GLUCAGON Presented By Daniel Vakili. Familiar Analogy.
GLUCAGONPresented By Daniel Vakili
Familiar Analogy
Familiar Analogy
GlucagonGlucagon Receptor
Target Tissue with stored glucose
Glucose
Structure
>29 amino acid polypeptide hormone
>nonsteroid
Where does it come from?>Synthesized and secreted from alpha cells in the islets of langerhans in the pancreas.
> Cleaved from proglucagon
Action
>Raise Blood Sugar
- Glycogenolysis
- Gluconeogenesis
>Target tissues
- Liver, Muscle, Fat
>Glucagon and Insulin are part of a feedback system that keep blood sugar at normal levels
ReceptorG-Protein Coupled Receptor
> Part of the GPCR Family
>Heptahelical
> Extracellular region binds to ligands
> Intracellular region interacts with multi-subunit G-Protein
Receptor
> Ligand activates
> GDP-GTP
> alpha subunit dissociates
cAMP: a secondary messengercyclic adenosine monophosphate
Glucagon-Receptor > G-proteins dissociate > α subunit-adenylate cyclase > cAMP > removes inhibitory subunit of PKA
Normal Blood Values
Insulin and Glucagon normally keep plasma glucose
>below 170mg/dl after a meal (absorptive state)
>above 50mg/dl between meals(postabsorptive state)
Too Little Glucagon: Hypoglycemia
> Symptoms: tremor, hunger, weakness, weakness, blurred vision, and mental confusion.
Too Much Glucagon:
>Glucagonoma- tumor of alpha cells resulting in overproduction
> Hyperglycemia
> Ketoacidosis - fatty acids to Ketone bodies
> Gluconeogenesis - Weight loss, anemia, ketoacidosis, diabetes mellitus.
Conclusion
Glucagon is a hormone antagonist to insulin, signaling the release of glucose from storage into the blood through glycogenolysis and gluconeogenesis.
Important for maintaining homeostasis.