Transcript GLUCAGON

GLUCAGON
Presented By Daniel Vakili
Familiar Analogy
Familiar Analogy
Glucagon
Glucagon
Receptor
Glucose
Target Tissue with
stored 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
Receptor
G-Protein Coupled Receptor
> Part of the GPCR
Family
>Heptahelical
> Extracellular
region binds to
ligands
> Intracellular region
interacts with
multi-subunit GProtein
Receptor
> Ligand
activates
> GDP-GTP
> alpha
subunit
dissociates
cAMP: a secondary messenger
cyclic 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.