Week 16- Unit 4 Flashcards
What are the alternative counter-regulatory hormones to focus on (5) ?
- Somatostatin
- Growth Hormone
- Catecholamines (norepinephrine and epinephrine)
- Glucocorticoids (cortisol - steroid hormones)
- Thyroid Hormone
What are the “peptide hormones” ? (4)
What do they all signal through?
Insulin
Glucagon
Somatostatin
Growth Hormone
-signal through binding of a cell membrane receptor
The Catecholamines ( nor and epinephrine) are _______ type hormones, they also signal through _______ ______ specifically the ___ or ____ adrenergic receptors.
Amine
Membrane receptors
Alpha or Beta Adrenergic
Glucocorticoids (cortisol) are ______ that signal through _______ receptors that function as ________ ________.
steroid
intracellular
transcription factors
Thyroid hormone is different from all the other hormones as it is a ________ type hormone but signals similar to the _______ types by binding to an ________ receptor and functioning as a transcription factor.
Peptide
Steroid
Intracellular
Insulin is secreted from ______ cells of the ______. It will suppress glucagon release from ______ cells.
(anabolic processes)
Beta
Pancreas
Alpha
Glucagon is secreted from _______ and _____ cells in pancreas. It can also stimulate the release of insulin in such a way that helps regulate ______ and ______ to maintain blood glucose. Without this regulation, Glucagon can precipitate __________ such as in diabetic ketoacidosis.
Alpha and L cells
GNG
Glycogenolysis
Hyperglycemia
Somatostatin is an general _______ for the release of other hormones. It is secreted as a ______ molecule much like insulin and glucagon, meaning it is secreted in _____ form that requires cleavage of the active peptide.
Inhibitor
Pro-molecule
Peptide
Somatostatin is secreted from several sites, mainly what 4 areas?
Hypothalamus
D cells of pancreatic islets
Central Nervous system
Gastric/intestinal mucosa
Somatostatin is secreted in response to what 3 MOLECULES mainly?
Glucose, Arginine, Leucine
What HORMONES can stimulate the release of Somatostatin ?
Glucagon
VIP
Cholecystokinin (CCK)- in Duodenum
Somatostatin will signal via a ______, activating an ______ G-protein which will then _______ adenylate cyclase. This will _______ cAMP.
GPCR
inhibitor
inactivate
decrease
Besides the main GPCR inhibitory pathway for signaling, Somatostatin can also activate several ______, _______ and _______.
Phosphatases
MAPK cascades
Ca+2 (calcium mediated signaling)
Somatostatin’s primary action is to decrease ______ will suppress the release of many hormones including what 4 ?
cAMP
Growth Hormone
TSH
Insulin
Glucagon
Somatostatin will also ______ gastric emptying by impacting the secretion of gastric and pancreatic _______.
Decrease
enzymes (required for digestion)
Glucagon can stimulate the release of both _____ and _____ in the pancreas.
Somatostatin (Delta cell)
Insulin (Beta cell)
Insulin will inhibit the release of ______ but does not necessarily effect the release of ______.
glucagon
Somatostatin
The action of Somatostatin being able to ____ both glucagon and insulin in a regulatory feeback look is necessary so Blood glucose can ______ again to stable levels before ______ is released again into the body.
inhibit
rise
insulin
Growth Hormone is a water _____ polypeptide with a very _____ half-life in circulation of ___ to ___ minutes.
soluble
Short
20 to 50
Growth hormone (GH) is composed of a _____ polypeptide chain in a spiral with ____ ____ bonds.
single
2 disulfide
Growth hormone is release from the ______ _____ gland. Starting at the ______ any number of stimuli can impact the release of _____ that will travel to the location of GH release.
Anterior pituitary
Hypothalamus
Growth Hormone Releasing Hormone (GHRH)
What are 4 examples of factors that can stimulate release of GHRH from they hypothalamus?
Sleep Rhythms Low blood glucose High blood AA Stress Exercise
After it is released from the Hypothalamus, GHRH binds to the ______ _____ of cells in the ______ ______. This results in the release of _____ by way of any number of second messengers including cAMP or Ca+ mediated signaling.
plasma membrane
Anterior Pituitary
Growth Hormone
After release from the anterior pituitary, Growth Hormone will travel in the blood to the ______ and interact with receptors similar to ______ _____ receptors. This will stimulate the release of ______ from the liver.
Liver
Jak-STAT
Insulin-like Growth Factor 1 (IGF-1)
IGF-1 will be similar to insulin by binding a plasma membrane _____ _____ for signaling. It regulates itself for feedback at several different levels.
Tyrosine kinase
Growth Hormone will feedback and inhibit the release of ______ in the Hypothalamus.
Similarly, _____ will feedback and inhibit its release from the Hypothalamus as well.
GHRH
IGF-1 (from liver)
IGF-1 can directly inhibit the release of _____ at the Anterior Pituitary gland. It will inhibit the release of _____ from the Hypothalamus, and then it will also STIMULATE the release of _______ from the Hypothalamus.
GH
GHRH
Somatostatin (will travel to inhibit release of GH at anterior pituitary)
The primary physiologic factors effecting stimulation of release of Growth Hormone depend on fuel availability. If Blood Glucose is _____ after meals , it will stimulate release of GH and GH helps reduce Glucose _____ and increases ______.
Low (GH helps increase blood glucose)
uptake
GNG
GH is released in response to ____ blood glucose and ______ blood levels after meals. The other three main stimulating factors are ?
low
AA
Sleep, Stress, Exercise
What will suppress the GH secretion at the physiological level after meals ?
High blood glucose after meals
High blood Fatty Acids
Release of GH can also be stimulated with pharmacological means such as addition of _______ or it can be inhibited by the introduction of _______.
GHRH
Somatostatin
Pathological states such as Starvation where energy is extremely low, will elicit the _____ of growth hormone release. This helps influence the pathways of ____ and _____ as a means of providing energy.
Stimulation
GNG
Lipolysis
Pathological states such as Obesity, Hypothyroidism, Hyperthyroidism will ______ growth hormone secretion.
suppress
For a GH receptor, they ______ upon ligand binding. However the receptors themselves lack _____ activity, so they are associated with _____ family of kinases.
dimerize
kinase
Jak2
The Jak2 (JAK) family of kinases that associate with GH receptor will phosphorylate the receptor after dimerization from ligand binding, this will then phosphorylate and activate ________, _______, or ______ signaling that all can have a cellular effect.
STAT (1,3,&5)
MAPKs
Phosphoinostitol kinases (PI3K)
GH as a physiological effect can be considered a means of _____ energy. It leads to a “muscle building” environment.
increasing
GH will effect the Adipose by ______ lipolysis by increasing the sensitivity of the tissue to _________. This will then in turn stimulate lipolysis by phosphorylation of ________.
This is a means of decreasing fat storage—>lean athletic physique.
increasing
epinephrine
Hormone sensitive lipase
In the Skeletal muscle, GH will increase ______ uptake and oxidization by the muscle.
This generates _____.
GH also increases ______ transport and uptake which will lead to increased _____ _____.
Free Fatty Acid (FFA - came from adipose)
ATP
AA
Protein Synthesis
In the liver, GH will ______ GNG and decreases ______ uptake to maintain blood levels, then increasing glycogen synthesis (even though counter intuitive, it is making energy and storing it too)
increase (GNG)
Glucose
In the liver, GH will also increase _______ uptake that will be oxidized to Acetyl CoA which increases substrate for ______.
FA
Ketogenesis
In the liver, because GH will decrease glucose uptake and increase ketogenesis (FA uptake too), this will contribute to ______ blood glucose levels and increased energy reserves.
elevated
Most importantly , GH will stimulate the release _____ and _____ that illicit the indirect effects of GH release on the body.
IGF-1
IGF-2
(2 Isoforms)
What cells in the Anterior Pituitary Gland will release Growth Hormone?
Somatotrophs
IGF can function in both an ______ and ______ way after being produced after the binding of GH to its Jak-STAT family Receptor on the liver.
Endocrine
Paracrine
IGF can act as a paracrine by binding to its own receptor on the ______. This receptor is similar to a ____ ___ (insulin like receptor with endogenous activity)
Liver
Tyrosine Kinase
The cascade initiated by IGF binding its own receptor in a Liver cell (paracrine) will cause a ________ response. This allows the cell to grow.
Mitogenic
As an autocrine, IGF will be similar to activites of ______ and it also has an influence on bones (long bones) on _____ or growth of the bone.
Insulin
Sulfation (needed for bone growth)