Cell Signaling Pathways: Steroid Hormones (Sex Hormones) Flashcards
What are the two main things that make up hormones?
Amino acids and cholesterol
What are some examples are steroid hormones?
progesterone, cortisol, aldosterone, testosterone, and estradiol
common structure of steroid hormones
4 carbon rings
Where are progesterone, cortisol, and aldosterone made?
adrenal cortex
Where is testosterone made?
in the testes
Where is estradiol made?
in the ovaries
What layer of adrenal cortex is androgen made?
inner layer
What layer of adrenal cortex is cortisol made?
middle layer
What layer of adrenal cortex is aldosterone made?
outer layer
How are hormones moved throughout the circulation?
They bind to plasma proteins and allow for the circulation of the hormones
What is the biologically active form of hormones?
the ones that are not bound to plasma proteins
When measuring hormone levels in the body, what is being measured?
the concentration of free hormone not bound to a protein
Are genomic hormones fast or slow acting?
slow
do steroid hormones bind extracellularly or intracellularly?
intracellularly in most cases
process of hormones affecting genome:
-enter the cell
-bind to protein to be able to enter the nucleus
-bind to DNA in the nucleus
-cause genomic effects
process of nongenome affecting hormones
-bind to cell surface receptor
-activate secondary messenger
-cell signaling event for the effect
FAST
Examples of lipid soluble hormones that bind to members of nuclear steroid superfamily:
cortisol, retinoic acid, thryoxine
Do steroids bind to random segments of DNA?
no, they have specific nucleotide sequence that they bind to
What are natural steroid hormones derived from?
cholesterol
Can steroid hormones pass through the cell membrane?
Yes, they do not always need a cell surface receptor
What mediate genome actions?
nuclear receptors
Where are glucocorticoids made?
adrenal cortex
What are the functions of cortisol?
increase blood sugar, suppress immune system, and aid in metabolism of fat, protein, and carbohydrates
-also decrease bone formation
-anti-inflammatory effect
Signaling process of glucocorticoids:
bind to intracellular receptors that are associated with heat shock proteins (heat shock prevent the binding to DNA before hormone binds)
-once the hormone binds, the heat shock protein leaves
-goes and bind to DNA
Glucocorticoids do what to the inflammatory and immune response?
Decrease
-increased bruising
-limit inflammatory response
-reduce cytokines and T cell activation
-reduce immunity in the body
What is cortisone?
synthetic corticosteroid
-not specific affects
-can have off target effects
-cause increased blood glucose and cause bone to breakdown
Function of NSAIDs:
anti-inflammatory that has specific targets
-inhibit cyclic oxygenase
-decrease inflammation
When are glucocorticoids taken?
after organ transplants to reduce the possibility of rejecting the organ
-do not prevent infection by themselves
-decrease immune system and actually increase the risk of infection
-synthesis regulated by corticotrophin releasing hormone
What is osteoporosis?
decrease in bone density due to decrease osteoblast activity and increase osteoclast activity
What happens to estrogen after menopause?
it decreases
What happens as a result of decreased estrogen?
bone loss
What are SERMS?
selective estrogen receptor modulators
-are not estrogens so do not have as many side effect with breast and cervical cancers
Examples of androgens:
-dehydroepiandrosterone (DHEA)
-androstenediol
-androstenedione
-testosterone
5alpha-dihydrotestosterone
Clinical use of androgen
-male androgen insufficiency
-treatment of children with failure to grow
-bone marrow stimulation
-masculinizing hormone therapy
Anabolic steroids
synthetic testosterone
-made in 1930 to stimulate puberty in boys and to treat chronic wasting disease
-large health risks (high cholesterol, acne, high BP, liver damage, and changes in left ventricle)
Androgen insensitivity syndrome
mutations in hormone binding region cause absence of hormone binding leading to testicular feminization
Mutations in estrogen receptors
-found in breast cancer, endometrial disease, and some psychiatric disease
Nongenomic steroid hormone action
response to receptor binding that does not initially influence gene expression
-involve signaling cascade
-may or may not result in gene expression
Cushing syndrome is a disorder that occurs when your body makes too much of cortisol over a long period of time. Which of the following symptoms is not expected in a patient with Cushing’s syndrome?
decrease in blood sugar
how do steroid hormones travel in the blood?
bound to carrier proteins due to their lipid or hydrophobic properties
