Rose: Intro to Endocrine

Question 1

What are the three types of hormones?

Answer 1

Peptide-protein
lipid
nonpeptide AA based

Question 2

What level of hormone do you need to exert an effect?

Answer 2

LOW concentration (nano/pico levels)

Overwhelming the system w/ high concentrations wipes out regulatory aspect

Question 3

What happens when free hormone binds a receptor? Is this reversible or irreversible? What turns free hormone into inactive products?

Answer 3

Forms hormone receptor complex> secondary messenger systems> trxn in target cells

REVERSIBLE

Liver and kidney

Question 4

If there are a limited number of hormone receptors on a cell than the receptors are…

Answer 4

saturable

Question 5

How do hormones and their receptors vary in specificity?

Answer 5

A given hormone may bind to multiple receptors with varying specificity, and a given receptor may bind multiple hormones with varying specificity.

Question 6

What releasing hormones does the Hypothalamus secrete?

Answer 6

GnRH
CRH
TRH
GHRH

Question 7

What inhibitory hormones does the hypothalamus secrete?

Answer 7

Somatostatin

Da

Question 8

What hormones does the anterior pituitary secrete?

Answer 8

ACTH
TSH
FSH
LH
GH
Prolactin

Question 9

What hormones does the posterior pituitary secrete?

Answer 9

Vasopressin

Oxytocin

Question 10

What hormones does the thyroid gland secrete?

Answer 10

T3/T4

Calcitonin

Question 11

What does the Parathyroid gland secrete?

Answer 11

Parathyroid hormone

Question 12

What does the adrenal gland secrete?

Answer 12

cortisol
aldosterone
androgens
estrogens
Epi

Question 13

What does the pancreas secrete?

Answer 13

Insulin
glucagon
somatostatin

Question 14

What do the ovaries secrete?

Answer 14

estradiol

progesterone

Question 15

What do the testes secrete?

Answer 15

testosterone

Question 16

What regulates Ant Pit hormone production and secretion?

Answer 16

Hypothalamus

Question 17

What happens to hypothalamic neurons in the post pit?

Answer 17

they extend into the post pit and can release neural hormones

Question 18

What two hormones are released from hypothalamic neurons in the post pit and immediately enter the general circulation?

Answer 18

ADH
Oxytocin

*target cells see stimulatory hormone very quickly

Question 19

What are the two affects that the portal system may have on anterior pit cells?

Answer 19

Hypothalamic hormones are released in the local portal system and bath ant pit cells leading to the production and release of hormone into the general circulation

Question 20

What limits the amt of hormone release?

Answer 20

Negative feedback

*MC mechanism

Question 21

When the thyroid hormone curtails THE release of TRH and TSH this is an example of…

Answer 21

neg feedback

Question 22

When does positive feedback occur?

Answer 22

RARE
Reinforcing “snow ball effect” resulting in MORE of the hormone secretion

e.g., effects of very high ovarian estrogen on OVULATION

Question 23

What is the diff between short and long feedback loops in the HPE Axis?

Answer 23

Long: increased hormone from the perpiheral endocrine gland–> inhibition of hypothalamus and pituitary

Short: Pituitary hormone –> inhibition of hypothalamus

Question 24

What are examples of AA derivative hormones?

Answer 24

TH
catecholamines
Tryptophan

Question 25

What are examples of lipid hormones?

Answer 25

Steroid hormones* | Eicosanoids (PG, LK)

Question 26

What are examples of peptide hormones?

Answer 26

GH PRL Many others

Question 27

Where is the preprohormone synthesized and cleaved into the prohormone?

Answer 27

RER mRNA on ribosome binds AA into a peptide chain...this is the PREprohormone

Question 28

What happens to prohormone?

Answer 28

``` Prohormone> GA (enzymatic cleavage)> Mature hormone> packaged into secretory granules> signal causes secretory granules to fuse with the PM> releases hormones ```

Question 29

Are protein hormones soluble in water?

Answer 29

YES!

Question 30

What can transport protein hormones and what does this do?

Answer 30

Carrier proteins 1. increases total amt of hormone in circulation 2. protects from metabolic brkdwn

Question 31

What peptide hormones are made as inactive preprohormones?

Answer 31

TRH

Question 32

What peptide hormones are made as inactive prohormones?

Answer 32

Pro-oplomelanocortin> ACTH Proinsulin> Insuline

Question 33

Where are steroid hormones derived from?

Answer 33

cholesterol (usually from plasma)

Question 34

Where is cholesterol produced and secreted? Are they stored? How are they transported?

Answer 34

cholesterol> enzymatic action in MITOCHONDRIA and SM ER> produced and secreted WITHOUT STORAGE> move DOWN concentration grandients

Question 35

What percent of steroid hormones are bound to carrier proteins? Are they water soluble?

Answer 35

99.9% bound NOT water soluble

Question 36

What component of steroid hormones enters the target cell?

Answer 36

FREE hormone

Question 37

What are two types of glands that synthesize steroid hormones?

Answer 37

gonads | adrenal glands

Question 38

What hormone is a biologically active lipid mediator that tend to occur at LOW levels in TISSUES and work LOCALLY?

Answer 38

Eicosanoids *drugable target

Question 39

What three classes of enzymes produce eicosanoid hormones and are derived from ARACHIDONIC ACID?

Answer 39

cyclooxygenases (COX-1 and COX-2): prostaglandins, thromboxanes lipoxygenases (LOX) leukotrienes cytochrome P450 mono-oxygenases: epoxides

Question 40

Ccyclooxygenases (COX-1 and COX-2):

Answer 40

prostaglandins thromboxanes *TARGET FOR ANTI-INFLAM

Question 41

lipoxygenases (LOX)

Answer 41

leukotrienes

Question 42

cytochrome P450 mono-oxygenases:

Answer 42

epoxides

Question 43

How do eicosanoid hormones signal?

Answer 43

through TRANSmembrane receptors

Question 44

What type of receptors do PG and TX signal through?

Answer 44

G protein coupled transmembrane receptors

Question 45

What are examples of Amine (tyrosine and tryptophan) hormones?

Answer 45

Catecholamines (DA, NE, Epi) Thyroid hormones (T4, T3)

Question 46

How are catecholamines similar to protein hormones?

Answer 46

bind G protein coupled transmembrane receptor (released on demand)

Question 47

How do thyroid hormones act like steroids?

Answer 47

bind to receptors that belong to the nuclear receptor superfamily> secretion involves diffusion down conc gradient

Question 48

What can down regulate receptors on target cells?

Answer 48

Decreasing receptor number Increasing degradation of hormone in cells Example: In the breast, estrogen reduces the number of estrogen receptors

Question 49

What an upregulate hormones?

Answer 49

Increasing receptor number Decreasing intracellular degradation of hormone Example: In the breast, estrogen increases the number of progesterone receptors.

Question 50

How do G proteins transduce signaling cascades?

Answer 50

1. stimulated AC> cAMP 2. increase cytoplasmic Ca 3. Activate phospholipase C> DAG and IP3

Question 51

How do protein hormones signal using G proteins and adenylate cyclase?

Answer 51

``` Hormone bound receptor> activates G-protein > stimulates Adenylate Cyclase> produces cAMP > activates protein kinase signal transduction ```

Question 52

How are steroid and thyroid hormone receptors different from protein hormone receptors?

Answer 52

Hormone binding to receptor> acts as transcription factors *Nuclear Receptor Superfamily

Question 53

What are steroid hormone receptor ligands of the nuclear receptor superfamily?

Answer 53

``` Estrogens progesterone androgens glucocorticoid mineralcorticoid ``` *transcriptional activation requires formation of hormone: receptor HOMOdimer

Question 54

Describe the pathway for steroid receptor signaling.

Answer 54

Free Hormone dissociates from carrier protein and enters the cell. Hormone binds to cytoplasmic receptor and translocates to the nucleus. Dimers form and sit down on specific steroid hormone response element contained on a subset of genes. Transcription of mRNA. Translation to protein. Hormone cellular response

Question 55

What is an example of transcriptional activation of RXR: TR Heterodimer?

Answer 55

Thyroid hormone T3 binding to TR

Question 56

Why is it important ot know about the nuclear family superfamily?

Answer 56

The receptors are important drug targets: ``` Thyroid supplementation targets T3R Glucocorticoid therapies targets GR Type II Diabetes treatment targets PPAR Vitamin D responses due to VDR Progesterone therapy during pregnancy targets PGR ```

Question 57

Where are hormones degraded?

Answer 57

Liver or kidney w/ excretion in the URINE or BILE **Carrier proteins protect extend half life of hormones by protecting them from liver/kidney metabolism

Question 58

Why are hormones secreted from the hypothalamus in PULSES?

Answer 58

Prevents desensitization of downstream hormone receptors *pulsatile secretion is a hallmark feature of the endocrine system

Question 59

What happens if there is continuous administration of hypothalamic hormones?

Answer 59

down regulates hormone receptors leading to a general reduction in hormone signaling *flat lines axis and pt can't respond on their own

Question 60

How does the sleep cycle affect hypothalamic hormone secretion?

Answer 60

It can affect the circadian rhythm of hormones and would affect when you want to take blood sample

Question 61

It often takes multiple hormones to affect cells and tissues. The effect of multiple hormones can be...

Answer 61

additive or synergistic

Question 62

What does it mean if a hormone is permissive?

Answer 62

allows another hormone to exert its full effect *required for full potential of another one

Question 63

What does it mean if a hormone is antagonistic?

Answer 63

diminishes the effect of another hormone