Catechol And Steroids Flashcards
Steroid hormones had been known to exist since the_____
-However, it was not until the early 1960s that the idea of ______ began to emerge.
early 20th century.
specific hormone-binding molecules in the target tissues of these hormones
Analysis of the steroid hormone receptors had relied largely on____ techniques. It is only after the genes encoding these receptors were___, it became possible to carry out detailed studies on the various functional domains of receptors.
biochemical
cloned
Testosterone:
- This is an ___ogen,male sex hormone
- synthesized in the ____
- It is responsible for secondary male sex characteristics.
Estradiol:
- an __ogen
- principal female sex hormone
- produced in the___
- responsible for secondary female sex characteristics
andr
testes
estr
ovary
Cortisol:
- This ___corticoid is synthesized from____ in the ____ of the _____
- It is involved in stress adaptation, elevation of blood pressure and Na+ uptake, numerous effects on the immune system
gluco
progesterone
zona fasciculata of the adrenal cortex.
Aldosterone:
- the principal _____corticoid
- produced from_____ in the____ of ____
- raises blood pressure and fluid volume, increases Na+ uptake.
mineralo
progesterone
zona glomerulosa of adrenal cortex
Progesterone:
- It is produced directly from____ and secreted from the____
- It is responsible for changes associated with___ phase of the____ cycle.
- It is also involved in the differentiation of____
pregnenolone
corpus luteum.
luteal
menstrual
mammary glands
Synthetic steroid hormones
Glucocorticoids
-___,____,____
Mineralocorticoid
-___
Androgens:
-___,____
prednisone,dexamethasone,triamcinolone
fludrocortisone
oxandrolone, nandrolone
______ is also known as anabolic steroids
nandrolone
Synthetic steroid hormones
Estrogens:
-_____(DES)
Progestins:
-___,____
diethylstilbestrol
norethindrone, medroxyprogesterone acetate
Cellular Localization of Steroid Receptors
- It is generally thought that unoccupied steroid receptors can exist in the____, while occupied receptors act in the____ on ____
- When bound to hormone,____ receptors move into the_____
cytoplasm
nucleus on target DNA
cytoplasmic
nucleus
CATECHOLAMINES
- catecholamine is a ____amine neurotransmitter
- an organic compound that has a____ ring and a____ amine
mono
catechol; side-chain
Catechol is a____ with ______side groups next to each other
benzene
two hydroxyl
Catechol can be either a___ molecule or a substituent of a___ molecule, where it represents a____ group.
-Catecholamines are derived from the amino acid____, which is derived from___ sources as well as synthesis from____
free
larger
1,2-dihydroxybenzene
tyrosine
dietary
phenylalanine
-Catecholamines are water-insoluble
T/F
F
Catecholamines are __% bound to____ in circulation.
50
plasma proteins
Release of the hormones epinephrine and norepinephrine from the_____ of the adrenal gland is part of the fight or flight response
-Tyrosine is created from_____ by____ reaction by the enzyme_____
adrenal medulla
phenylalanine
hydroxylation
phenylalanine hydroxylase
Catecholamine-secreting cells use several reactions to convert tyrosine serially to____ and then to____
L-DOPA
dopamine
amphetamines are catecholamine analogues.
T/F
T
Structure of Catecholamines
- Catecholamines have the distinct structure of a____ ring with_____ groups, an intermediate____, and a terminal___.
- Phenylethanolamines such as norepinephrine have a____ group on the____ chain
benzene
two hydroxyl
ethyl chain
amine group
hydroxyl; ethyl
In humans, catecholamines are derived from the amino acid___
L-phenylalanine.
L-Phenylalanine is converted into _____by an___ amino acid hydroxylase (AAAH) enzyme (_____,found in large amounts in the____), with_____ and _____ as cofactors
L-tyrosine
aromatic
phenylalanine 4-hydroxylase
liver
molecular oxygen (O2) and tetrahydrobiopterin
L-Tyrosine is converted into ____by another AAAH enzyme (_____) with___,___,____ as cofactors.
L-DOPA
tyrosine 3-hydroxylase
tetrahydrobiopterin , O2, and ferrous iron(Fe2+)
L-DOPA is converted into___ by the enzyme aromatic L-amino acid____ (AADC) ,with___ as the cofactor.
dopamine
decarboxylase
pyridoxal phosphate
Why is ___ hard to measure in the brain
And how do we eventually do it
This step occurs so rapidly that it is difficult to measure L-DOPA in the brain without first inhibiting AADC.
Dopamine is converted into____ by the enzyme____, with___,_____,___ as cofactors.
norepinephrine
dopamine beta-hydroxylase(DBH)
O2, copper and L-ascorbic acid
Norepinephrine is converted into_____ by the enzyme_____ with_____ as the cofactor.
epinephrine
phenylethanolamine N-methytransgerase (PNMT)
S-adenosyl-L-methionine
rate limiting step in Catecholamines synthesis is the____
hydroxylation of tyrosine
Catecholamine synthesis is inhibited by____, which inhibits_____ enzyme
alpha-methyl-p-tyrosine (AMPT)
tyrosine hydroxylase
Insufficient amounts of phenylalanine hydroxylase result in_____, a metabolic disorder that leads to______ unless treated by____
phenylketonuria
intellectual deficits
dietary manipulation.
Location Of Catecholamines
-Catecholamines are produced mainly by the____ cells of the_____ and the____ fibers of the____ nervous system
chromaffin
adrenal medulla
postganglionic
sympathetic
Dopamine, which acts as an____ In the CNS, is largely produced in neuronal cell bodies in two areas of the____: the____ and ____
NT
brainstem
VTA and the SN
SN contains___ -pigmented neurons.
neuromelanin
Locus coreolus also has neuromelanin neurons
T/F
And produces ____
T
The similarly neuromelanin-pigmented cell bodies of the locus coeruleus produce norepinephrine
Epinephrine is produced in small groups of neurons in the human brain which express its synthesizing enzyme, PNMT, these neurons project from a nucleus that is adjacent (____) to the____ and from a nucleus in the____ region of the___ tract
ventrolateral
area postrema
dorsal
solitary
Degradation
- Catecholamines have a half-life of a____ when circulating in the blood.
- They can be degraded either by____ by COMT or by____ by MAO.
- MAOIs bind to___, thereby preventing it from breaking down catecholamines and other monoamines.
few minutes
methylation
deamination
MAO
Catabolism of catecholamines is mediated by two main enzymes:COMT which is present in the____ and ___ of the cell and MAO which is located in the______
-Both enzymes above require cofactors: COMT uses____ as a cofactor while MAO uses___.
synaptic cleft and cytosol
mitochondrial membrane.
Mg2+; FAD
The next catabolic steps in the pathway (after Mao or Comt) involves ___,____,____
- The end product of epinephrine and norepinephrine is _____which is excreted in the urine.
- Dopamine catabolism leads to the production of______
alcohol dehydrogenase,aldehyde dehydrogenase, and aldehyde reductase
vanillylmandelic acid (VMA)
homovanillic acid(HVA)
NE is a neuromodulator of both CNS and pns
T/F
T
High blood sugar levels can lead to stress which in turn leads to high Catecholamine levels
T/F
F.
Low blood sugar level
Extremely high levels of catecholamines (also known as____) can occur in CNS trauma due to stimulation or damage of nuclei in the____, in particular, those nuclei affecting the ____nervous system
In emergency medicine, this occurrence is widely known as a “_______”.
catecholamine toxicity
brainstem
sympathetic
catecholamine dump
Extremely high levels of catecholamine can also be caused by______ tumors in the______, a condition known as_____
neuroendocrine
adrenal medulla
pheochromocytoma
pheochromocytoma
Treatable or not treatable?
Treatable
High levels of catecholamines can also be caused by MAO-A deficiency, known as ——
MAO-A deficiency occurs in the absence of pheochromocytoma neuroendocrine tumors, and_____, but it looks similar to_____ with symptoms such as_____ and _____
Brunner syndrome.
carcinoid syndrome
carcinoid syndrome
facial flushing and aggression.
Acute porphyria causes depressed catecholamine levels
T/F
F
Causes elevated levels
Effects Of Catecholamines
- Some drugs, like____ raise the levels of all the catecholamines.
- Increased catecholamines may also cause an increased respiratory rate (_____) in patients.
- Catecholamine is secreted into___ after being broken down, and its secretion level can be measured for the diagnosis of illnesses associated with catecholamine levels in the body.
tolcapone
tachypnoea
urine
Tolcapone is a _____
central COMT-inhibitor
____testing for catecholamine is used to detect pheochromocytoma
Urine
MAO inhibitors:
-found in____,___,____
neural tissue, gut and liver
Antidepressants are MAO enhancers
T/F
F
Drugs that block the activation of beta receptors (beta blockers), such as___, are often given to patients with___,____, or chest pain (____). These drugs are contraindicated in patients with asthma because they_____
propranolol
tachycardia
high blood pressure
angina pectoris
worsen bronchial constriction.
Catecholamines play a key role in nutrient metabolism and the generation of body heat (thermogenesis).
T/F
T
Catecholamines stimulate ___lysis and the breakdown of____.
glycogeno
triglycerides
Catecholamines can regulate the secretion of multiple hormones.
T/F
T
dopamine inhibits____ secretion
norepinephrine stimulates ____hormone secretion
epinephrine inhibits____ secretion
prolactin
gonadotropin-releasing
insulin
Parathyroids
Location - ___ or ___ small round bodies on the posterior surface of the lateral lobe of the thyroid gland
4 or 5
Parathyroids
Function:
- secretes the ____ hormone that controls Blood ___ homeostasis
- increases ___and____ absorption from the Intestines, Kidneys and Bones
- increases _____ excretion [lowers blood phosphate levels]
Parathyroid
Calcium
Ca+2 and Mg+2
PO-3
Disorders of parathyroid activity
Hypocalcemia
- causes by ___secretion of PTH
Hypercalcemia
- causes by ___secretion of PTH
hypo
hyper
Hypocalcemia can result in tetany
T/F
T
Over secretion of ___ , results in a fibrous bone disease [_____or also called ________Disease of the bone]
PTH
osteitis fibrosa cystica
Von Recklinghausen’s
Glucocorticoids produced by cells of the Zona _____
Mineralocorticoids - produced by the cells of the Zona ____
Gonadocorticoids - produced by cells of the Zona _____
Fasciculata
Glomerrulosa
Reticularis
Glucocorticoids promotes protein and fat catabolism
Mineralocorticoids:
aldosterone causes Sodium, Potassium ,and water retention
Glucocorticoids reduce blood pressure
Aldosterone increases blood pressure
T/F
T
F
F
T
Glucocorticoids promotes vasoconstriction
T/F
T
Mineralocorticoids promotes stress resistance through Anti-Inflammatory actions
T/F
F
It’s glucorticoid
Glucocorticoids aids gluconeogenesis
T/F
F
Aids glycogenolysis
Addison’s Disease
- caused by ___secretion of Cortical hormones
- results in __reased blood potassium levels
- results in ___reased sodium retention and dehydration
- results in ___reased blood glucose levels
- results in ___reased blood pressure
- results in ___reased stress resistance
- results ___reased risk of kidney failure
Hypo
inc
dec
dec
dec
dec
inc
Cushing’s syndrome
- causes by ___secretion of Cortical Hormones
- results in shifts of the body __ to the__ and ____
- results in general body weakness
Hyper
fat
face and shoulders
Cushing’s syndrome
results in altered carbohydrate & electrolyte metabolism
T/F
T
Adrenogenital Syndrome
-caused by ___secretion of____
Hyper
Gonadotropins
Adrenogenital Syndrome
results in premature sexual development in only males
T/F
F
Both males and females
Adrenogenital Syndrome
results in masculinization of females
T/F
T
Adrenal Medulla Hormones -
_____ and _____
Epinephrine & Norepinephrine
Effects of Adrenal Medulla Hormones are parasympathomimetic
T/F
F
Sympathomimetic
Effects of Adrenal Medulla Hormones
Increased respiratory rate and ___ of bronchioles
dilation
Pancreatic Hormones
Insulin
- secreted by the ___ Cells
- promotes (lower or higher ?) blood glucose levels by: promoting glyco__
Beta
Lower
genesis
Insulin
Inhibits protein synthesis
T/F
F
Insulin
Promotes lipogenesis
T/F
T
Pancreatic hormone
Glucagon
- secreted by the ____ Cells
- promotes (lower or higher?) blood glucose by: promoting glyco____
Alpha
Higher
genolysis
Oxytocin and vasopressin both consist of only ___-amino acid residues only.
9
Glycoprotein Hormones:
They are conjugated protein where carbohydrate groups are ____,____,____etc.
mannose, galactose, fucose
Group 1 hormones possess relatively shorter half-lives (minutes or seconds)
T/F
F
possess relatively longer half-lives (hours or day)
Group 2 hormones possess short half-lives (in minutes).
T/F
T
Primary endocrine organ failure can only be genetic
T/F
F
Can be genetic or acquired
adrenal insufficiency can be due to _____ enzyme deficiency)
21-hydroxylase
Hashimoto’s hyperthyroidism is an Autoimmune disease
T/F
F
Hypo *
iodine deficiency leading to decreased _____ hormone synthesis
thyroid
hypothyroidism due to hypopituitarism is an example of ______
Secondary endocrine organ failure
