Hormonal Regulation of Metabolism Flashcards
In what order are body fuels used?
8 hrs: Liver glycogen depleted
24 hrs: Triglycerides provide energy for body, Protein degradation provides glucose for the brain
Several Days: ketone bodies used as alternative fuels
How does glucagon affect brain function?
It insures brain function as it releases fuels from liver glycogen (brain) and adipose triglycerides (body)
What energy processes involving glucagon happen in the liver?
Glycogenolysis
Gluconeogenesis
Fatty Acid Release
Ketone Body Syntheis
What does insulin insure?
Fuel storage (glycogen and fat)
What energy processes involving insulin happen in the liver?
Glycogen Synthesis
Glycolysis (AcCoA) Synthesis
Fatty Acid Synthesis
What hormones have a slower, but more prolonged mechanism of action than that of insulin, glucagon and epinephrine?
Cortisol
Thyroid Hormone
Leptin
Adiponectin
What kind of hormone is cortisol?
A steroid hormone
What triggers cortisol secretion?
Stress
Does cortisol secretion respond to hypothalmic/pituitary signals?
Yes, unlike other metabolic regulators
What is the pathway to cortisol secretion?
Hypothalmus secretes CRH into portal system > Anterior pituitary secretes ACTH into systemic circulation > Adrenal cortex responds with secretion of cortisol
What kind of precursor protein does ACTH come from?
A large precursor protein
What sort of effects does cortisol have on the body?
Elevate blood glucose
Mobilize fat
Increase muscle protein catabolism
Anti-inflammatory effects (well known)
What disease results from excess cortisol?
Cushing’s Syndrome
What are the symptoms of Cushing’s Syndrome?
Weight gain of upper body Easy bruising Purple stretch marks Excess hair growth or acne in women Menstrual disorder Faitgue & Muscle weakness Mood swings
What disease results from Cortisol deficiency?
Addison’s Disease
What are the symptoms of Addison’s disease?
Changes in blood pressure Chronic Diarrhea Patchy skin color Paleness Extreme weakness Loss of appetite Mouth lesions on buccal mucosa Nausea and Vomiting Salt Craving Sluggish Movement Unintentional weight loss
Converting thyroglobulin to T4 and T3
Thyroglobulin - Tyr to Thyroglobulin - Tyr - I to (via proteolysis) Thyroxin (T4) Triiodothyronine (T3)
What diseases result from Hypothyroidism?
Myxedema
Hashimoto’s Syndrome
What are the symptoms of Hypothyroidism?
Cold sensitive Unintentional weight gain Fatigue Brittle hair/nails Constipation Depression
What is another name for congenital hypothyroidism?
Cretinism
What disease results from Hyperthyroidism?
Grave’s Disease
What are the symptoms of Grave’s Disease?
Heat sensitive Unintentional weight loss Exopthalmia Irregular Heartbeat Insomnia Diarrhea Irritability Tremor
What is Leptin know as and what is it secreted by?
Leptin is known as the “set point” hormone.
It is secreted by fat
What type of receptor is the leptin receptor?
Orphan
What is the function of Leptin?
It maintains constant mass.
What is JAK?
Janus Kinase
What is STAT?
Signal Transducing Activator of Transcription
What happens to muscle when Adiponectin activates AMPK?
Up Fatty Acid Uptake
Up Beta Oxidation
Up Glucose Uptake
What happens to the liver when Adiponectin activates AMPK?
Up glycolysis
Down Gluconeogenesis
Down Fatty Acid Synthesis
What types of energy processes does AMPK inhibit and activate?
It inhibits energy consuming processes
It activates energy producing processes
What signaling pathway is used when bacterial products are present?
Toll Receptor/NFkB
What signaling pathway is used when glucocorticoids are present?
Transcriptional Regulation
What signaling pathway is used when Cytokines are present?
JAK/STAT
What signaling pathway is used when Thromboxane A2 is present?
Serpentine/PKC
What signaling pathway is used when Nitric Oxide is present?
Guanylate cyclase/PKG
What are toll receptors activated by?
PAMPs Pathogen Associated Molecular Patterns
What two major pro-inflammatory transcription factors are activated by toll receptors?
AP-1
NFkB
What is NFkB considered in inflammation?
It’s the master switch for inflammation
What does NFkB activate?
Gene expression for many inflammatory cytokines and synthetic enzymes for inflammatory mediators
What role does NFkB play in cancer?
Regulates synthesis of proteins that inhibit apoptosis (cIAPs)
What type of hormones are glucocorticoids?
Steroid hormones
Are steroid lipophilic or lipophobic?
Lipophilic
What type of signaling is the receptor enzyme Guanylate Cyclase like?
cAMP signaling
Does Guanylate cyclase require a G protein?
No
What does Guanylate cyclase activate ultimately?
cGMP - dependent protein kinase (PKG)
Where is Guanylate cyclase found?
Epithelium Heart Blood Vessels Brain Kidney Collecting Tubules
What function is Guanylate cyclase important in?
Blood pressure regulation
What are the 2 types of guanylate cyclase and what are they activated by?
1) integral membrane proteins are activated by atrial natriuretic factors (ANF)
2) cytosolic protein w/ associated heme is activated by Nitric Oxide (NO)
What is the function of ANF?
Enhances Na+ and H2O excretion in the kidney collection tubules
Makes the heart an endocrine gland and serves to decrease blood pressure
What was the first gas to be recognized as a biological messenger?
Nitric Oxide
What is the function of NO?
It is the blood pressure police
How are NO and nitroglycerin related?
Nitroglycerin slowly degrades into NO
What is angina due to?
Ischemia in area of heart muscle
What does NO do when it binds guanylate cyclase?
It increases cGMP which activates PKG
What does PKG result in?
Low cytosolic Ca2+ resulting in relaxation of heart muscle
What does cGMP Phosphodiesterase do?
breaks down cGMP to halt signal from ANF or NO
What drug is cGMP Phosphodiesterase inhibited by?
Viagra which leads to potentially localized vasodilation
