ANSC 113 Endocrinology notes

Why does the source of the primary endocrine organs (glands) matter in livestock?

The source can suggest the location or production site of action and overall function of hormone

What is Insulin?

A hormone

What triggered Insulin to be produced, what organ produced it?

Eating a meal, which caused the Pancreas to create Insulin

What is the impact of Insulin being released?

Takes Glucose out of blood and into the tissue

What process occurred to cause that impact of releasing Insulin?

Stretched receptors, which Afferent neuron into CNS, then it’s a Efferent neuron and then enters the pancreas

What are three things to focus on when figuring out a hormone or process?

1. What is the hormone

2. What is its trigger

3. What is it impacting

What is Hormone class is based on?

Chemical Origin

Knowing what a hormone is made of and/or derived, how it is shaped, will help in understanding what?

How a hormone behaves and the function it plays

What is Steroids derived from?

Cholesterol

What are proteins, polypeptides, and amines composed of/derived from?

Amino Acids

What is the common thing about amines?

Amines have nitrogen playing a role

Where do Eicosanoids come from?

Arachidonic acid or polyunsaturated fatty acids

What does polyunsaturated mean?

Fatty acids that have more than one double bond

How do steroids look like?

They have a ring structure

What hormone is lipid soluble

Steroids

Where do steroids come from and where are they released?

Steroids come from cholesterol and are released from glands: Adrenal, gonads, and placenta

How do steroids move? What is the word for this action?

Typically synthesized and carried from their gland to their target by bloodstream. It is an Endocrine action

Where organ does the steroid Progesterone come from?

Ovary

What organ does the steroid Cortisol come from?

Adrenal

Where is Cholesterol important in the cell?

It is important in the cell membrae

What are Polypeptides?

A chain of amino acids, less than 100, typically simple structure

What is a protein?

A chain of amino acids, more than 100, typically folded/includes additions (such as carbohydrates

Where are Proteins and Polypeptides secreted?

By the hypothalamus, pituitary, pineal, parathyroid, pancreas, gamete, uterus, etc.

What do proteins and polypeptides synthesize as and what might be needed by them?

Synthesize as preprohormone or pre hormone so proteins/polypeptides need to be activated or processed

Where do Proteins and polypeptides travel through

Neuroendocrine - travel through nervous system

Endocrine - bloodstream - travels far

Paracrine - close

Autocrine - really close

What are amines derived from?

Tyrosine - amino acid

How does amines act via?

Neural

Endocrine

Paracrine

Autocrine

What is the difference between Thyroid hormones T3 and T4, where are they made?

T3 has 3 Iodine and T4 has 4 Iodine, they are made in the thyroid gland

What is Indolamines? Where is it made?

A amine, and is serotonin or melatonin,

Where is melatonin made? What is one thing that controls its release?

It’s made in the pineal gland, and light can stop it from being released as your body thinks it’s daylight

Where is serotonin released?

Its released in the intestine and/or brain

What is Catecholamines? Where is it made?

Amines that are called dopamine, norepinephrine, and epinepherine

They are made in the brain, sympathetic nervous system, and adrenals

What is the eicosanoids structures

They have a fatty acid like structure

What are eicosanoids derived from?

Arachidonic acid

Polyunsaturated fatty acids - multiple double bonds

What are groups of eicosanoids

Prostaglandins, thromboxanes, and leukotrienes

Where are prostaglandins, thromboxanes, and leukotrienes produced and where do they act via what?

Produced by almost all organs

Act locally via endocrine, paracrine, and autocrine

What do Receptors do?

Help control the power and processes of a hormone

Why does location matter for hormone-receptor binding

Depending on where the binding happens, gives a different response

Why does abundance matter for hormone-receptor binding

The more receptors the more cells that can be combined

Why does specificity matter for hormone-receptor binding

If there is not a specific receptor than the hormone has nothing to bind with

Why does affinity matter for hormone-receptor binding?

Means how long can the hormone and receptor stay together

What does Aldosterone do? Where is it released?

Helps control blood pressure and mineral balance, and released by Adrenal cortex

What does Cortisol do? Where is it released?

Helps with stress response

Where is Estradiol produced and what is it?

It’s an estrogen, and produced in the Ovary

What is the parent compound for all strial hormones

Cholesterol

What is steroid hormone activity, what are the acts it does?

It does transcription and creates new proteins

What is another thing steroid receptors might help tell an animal? What is an example?

Steroid receptors might help tell the animal the final action, Example being it binds to vaginal epithelia and says to produce different proteins to make mucus look different

How does the steroid receptors enter the Nucleus?

By being carried by cytoplasmactic receptors that puts them into the nucleus

Steroids are always _________ from the precursors

Steroids are always on demand from the precursors

Steroids are released from parent cell through ______? What does that allow for the steroid to do?

Steroids are released from parent cell through simple diffusion, which allows steroids to not need a transporter and has a nature to cholesterol being part of the membrane which makes it easier to pass through.

How is steroids carried in the blood?

It’s carried by carrier proteins

What is the steroid half-life?

It has a long half-life, meaning it can stay in the blood for a long time

Where is location of receptors for steroids?

Nucleus and cytosol (cell membrane)

What is the response to receptor-ligand binding in steroids? What does it lead to?

Transcription and translation, it leads to proteins

What is the general target response?

New protein product

What are four examples of steroids?

Estrogen, Progesterone, Androgens, and Cortisol

If something traveling through Endocrine, what might it travel through?

Blood vessel, usually has a far destination

If something is traveling through Autocrine, what might it travel to?

It may travel to the same cell or same cell type

If something is traveling through Paracrine, what might it travel to?

It may travel to cells that are close by

What is the structure of a peptide?

Made of small proteins - 100 or less amino acids, a shorter simpler chain

What makes an Endoplasmic reticulum “rough”

The presence of ribosomes on the endoplasmic reticulum

What is the biggest difference between the peptide activity of hormones and steroids?

The way they respond in the target cell

Where is peptides/proteins stored in?

In advance and stored in secretory vesicles

How is peptides/proteins released from parent cell?

Exocytosis

How is peptides/proteins transport in the blood?

It freely dissolves in plasma

What is the half-life for peptides/proteins?

Short

What is the location of receptors for peptides/proteins

in cell membrane

What is response to receptor-ligand binding for peptides/proteins

A second messenger

What is the general target response for peptides/proteins

protein modification

What is examples of peptides/proteins

Insulin, Oxytocin, Parathyroid hormone, Gonadotropin Releasing Hormone

What is the difference between Steroid and peptide/protein hormone creation

Steroid is on demand and involves cholesterol, Peptide/protein is storage in vesicles and involves rough endoplasmic reticulum.

What is the difference between steroid and peptide/protein location

Steroid is inside cell and hydrophobic, peptide is outside of cell, on cell membrane

Steroid has a badge and peptides don’t

What is the difference between steroid and peptide/protein ligand-receptor binding

Peptides bind to receptor and have a second messenger, while peptides/proteins don’t need a receptor sometimes and go into the cell

What do Catecholamines, Indolamines and Thyroid Hormones come from? Which ones are stored and where at?

All are from Tyrosine, and Catecholamines and Thyroid hormone are stored in secretory vesicles while Indolamines is on demand

When released from parent cell, what do Indolamines and Thyroid hormones have in common and what does Catecholamines do differently?

Indolamines and Thyroid hormones are released through simple diffusion

Catecholamines are released through exocytosis

When transported in blood, what do Indolamines and Thyroid hormones have in common and what does Catecholamines do differently?

Indolamines and Thyroid hormones are bound to carrier proteins

Catecholamines are freely dissolved in plasma

What is the half-life for both Indolamines and Thyroid hormone and what is the half-life for Catecholamines?

Indolamines and Thyroid hormones have a long half-life

Catecholamines has a short half-life

Where is the location of receptor for Catecholamines and Indolamines and where is the receptor location for Thyroid hormones?

Catecholamines and Indolamines have their receptors in cell membrane

Thyroid hormones have their receptor in nucleus

What is the response to receptor-ligand binding in both Catecholamines and Indolamines, what is the response to receptor-ligand binding in Thyroid hormones?

Catecholamines and Indolamines have an activation of 2nd messenger

Thyroid hormones activate genes for transcription and translation

What is the general target for Catecholamines and Indolamines, what it the general target for Thyroid hormones?

Catecholamines and Indolamines general target is modifying existing proteins

Thyroid hormones general target is inducing new protein synthesis

What are examples of Catecholamines?

Epinephrine, Norepinephrine, and dopamine

What are examples of Indolamines?

Serotonin and melatonin

What are examples of Thyroid hormones

Thyroxine (T4) and triidothyronine (T3)

What does Catecholamines behave as?

As peptide hormones

What do Thyroid hormones behave as?

Like steroids

What do Indolamines behave as?

In the middle between peptide and steroids

What is the synthesis and storage of Eicosanoid?

On demand from precursor

How is Eicosanoid usually released from parent cell?

Diffusion, exocytosis

How is Eicosanoid transported in blood?

Usually not transported in blood, goes through autocrine or paracrine actions

What is the half-life for Eicosanoid?

Short

Where is the location for the receptor of Eicosanoid?

In cell membrane

What is the response to receptor-ligand binding of Eicosanoid

Activate 2nd messanger

What is general target response for Eicosanoid?

Modify existing proteins

What are examples of Eicosanoid?

Prostaglandins and Leukotrienes

What does positive and negative feedback regulate?

Hormone action

Effect of hormone is proportional to what?

to concentration of hormone available to bind to receptor

What does negative feedback do? What does it prevent?

reduces the activity of a pathway when the end product accumulates, preventing overproduction

What does positive feedback do?

Enhances activity of pathway, often to reach a threshold

What does Thyroid produce?

T3 and T4

What is Adrenal made up of and what do they each make?

Inner medulla - epinephrine and norepinephrine

Outer cortex - 3 zones - all make steroids, mainly cortisol