Integration Of Metabolism Flashcards
Leptin
- secreted by ADIPOCYTES
- Reports on the status of TAG stores
- Represses the desire to EAT
Where does EXCESS TAG get stored?
- Pancreas
- Muscles
- Liver
- Blood vessels
Fxn of Ghrelin
- Peptide secreted by the Stomach
- Acts on the Hypothalamus to stimulate APPETITE through its receptor
SOCS Knockout mice display what?
- Enhanced sensitivity to Leptin
- Resistance to weight gain
- even with a high fat diet
Type 1 Diabetes
Autoimmune DESTRUCTION of Beta cells
- Usually before the age of 20
Mnemonic for Leptin
Leptin won’t “Let Him” eat.
- So won’t “MS. H”
What kind of receptor does Insulin bind to?
Tyrosine-Kinase Receptor
Leptin binds to what kind of receptor in the Hypothalamus?
Arcuate Nucleus
Insulin deficiency or resistance can lead to what?
- Hyperglycemia
- Metabolic Syndrome
- Diabetes
GLP-1
- Glucagon-like Peptide 1
- Secreted by “L” cells in the INTESTINE
- Increases INSULIN secretion
- Increases insulin BIOSYNTHESIS
- Acts on the brain to induce the feeling of SATIETY
Ghrelin secretion increases _____ and decreases _____.
- BEFORE a meal
- AFTER a meal
Upon Leptin binding to it’s receptor, POMC is proteolytically processed to yield variety of signal molecules one of which is ______?
Melanocyte-Stimulating Hormone
Fxn of Leptin
- Increase the sensitivity of MUSCLE and LIVER to Insulin
- Stimulates Beta Oxidation of FA
- Decreases TAG Synthesis
A knockout in Leptin will lead to what?
Extreme Obesity
- Hyperphagia (Overeating)
- Hyperlipidemia
- Insensitivity to Insulin
When ATP is LOW, AMPK is _______?
Allosterically Activated
&
Phosphorylates many targets controlling cellular energy production and consumption
When ATP is HIGH, AMPK is ______.
INACTIVE
Type 2 Diabetes
- Normal or even HIGHER levels of Insulin in the blood
- Unresponsive to Hormone (Resistance)
Both Leptin and Adiponectin exert their effects through the Key regulatory enzyme, ________.
AMP- Activated Protein Kinase (AMPK)
Energy Consumed equals what?
Energy EXPENDED
+
Energy STORED
SOCS
Suppressor of Cytokine Signaling
- Disrupts the interactions of components of the Insulin-signaling pathway (Inhibits)
What enzyme is the “Tallest building that would be seen at 30k feet?”
AMPK
Where is energy stored in the body?
In TAG in the Adipocytes
What is a second population of neurons containing Leptin?
Proopiomelanocortin (POMC)
AMPL Activates what pathway?
FA Oxidation
Insulin
- secreted by the Beta cells of the Pancreas
- Reports on the status of Blood glucose
Obesity can be cause by a resistance to what?
Leptin
&/or
Insulin
Long term control over caloric homeostasis.
2 key signal molecules regulate energy homeostasis over the time scale of HOURS to DAYS
- Leptin and Insulin
What is the only organ that can carry out all the reactions of major pathways?
Liver
CCK binds to what type of receptor? Where?
- Binds to G-protein-coupled receptors
- Located in various peripheral NEURONS
What turns OFF the Insulin Signal?
A bunch of Phosphatases
Overview of Diabetes Mellitus
- Glucose is OVER produced by the LIVER
- Glucose is UNDERUTILIZED by other organs
Mnemonic for AMPK
Want to eat at “AMP……K”
Short-term Signals to induce satiety?
Relay the feelings of Satiety from the GUT to various regions of the BRAIN
- Reduces the urge to eat
- Use of CCK and GLP-1
CCK
- Cholecystokinin
- Secreted by the SMALL Intestine in response to a meal
- Acts on the brain to induce the feeling of SATIETY
- Can also potential INSULIN action in the Pancreas
- Stimulates the secretion of BILE Salts from the Gallbladder
What population of neurons expresses appetite-stimulating peptides?
- Neuropeptide Y (NPY)
- Agouti-related Peptide (AgRP)
(“Pie & AGRaPe)
Leptin is secreted in DIRECT proportion to what?
The amount of FAT present.
Leptin secretes signal molecules called _____?
Adipokines
- Leptin and Adiponectin
Most short-term signals are _______?
Appetite suppressants
CCK is secreted as a ______ signal.
Postprandial
What does Leptin inhibit?
NPY and AgRP
- Represses the desire to eat
