Intro to Endo Drugs Flashcards Preview

Block 8 - Endo & Repro > Intro to Endo Drugs > Flashcards

Flashcards in Intro to Endo Drugs Deck (17):
1

How is specificity achieved in endocrine signalling?

target tissue specificity: type and number of receptors in a tissue
hormone-receptor specificity: the ability of hormone to interact w its receptor, & not others

2

What are nuclear receptors?

ligand dependent transcription factors that work through common mechanism of action

3

How do hypothalamic releasing hormones get to the ant pituitary?

made by hypothalamic neurons, transported to median eminence, secreted into portal circulation
pulsatile action

4

What are the six steps in which defects in endocrine systems can occur?

hormone biosynthesis
transport to site of action
interxn w receptor on target
initiation of biological response (stimulus-response coupling)
termination/antagonism of response
degradation/elimination of hormone

5

What are the different causes for a lack of hormone?

incomplete biosynthesis (CAH)
reduce signal for synthesis/secretion (or no receptor for it)
hyperplasia/neoplasia
loss of gland that secretes hormone (type I DM, Hashimotos, Addisons)
iatrogenic suppression/loss of secreting gland

6

What are different things that can cause a hormone to be present but not work properly?

altered form of hormone
altered receptors --> HORMONE RESISTANCE (androgen insensitivity, laron's dwarfism)
post-receptor activity altered --> RESISTANCE (PTH resistance from mutations in G protein, insulin or GH resistance)
inappropriate secretion/release

7

What can secondarily alter the function of a hormone?

trauma or stress (insulin resistance during stress)
impaired hormone metabolism (impaired vitamin D --> hyperparathyroidism)
drug interxns w other hormone systems (something that displaces from carrying protein)

8

What things can cause hormone excess?

loss of negative feedback
hyperplasias/neoplasias

9

What are treatment options for a lack of hormone?

hormone replacement therapy
stimulate natural secretion - direct or indirect

10

What are treatment options for too much hormone?

inhibit biosynthesis or secretion
interfere w or oppose actions of hormones (functional antagonists)
remove gland, then hormone replacement

11

What are 5 determinants of hormone/drug action?

site of action (law of mass action)
hormone spillover
cross coupling
hormone and drug metabolism (drug-drug interxns)
stimulus-response coupling

12

What is hormone spillover responsible for?

lots of side effects seen w drugs and hormones - may just be able to reduce the dose

13

What is an example of cross-coupling?

estrogen cause increase in receptors for oxytocin on uterine muscle during 3rd trimester

14

How are steroids and peptides degraded?

steroids - converted to less active through oxidation and conjugation
peptides - degraded by proteolysis (can't take orally)

15

What are the different ways to measure hormones?

chemical (HPLC, chromatography/mass spec) - catecholamines and urinary cortisol
immunological methods (RIA, ELISA)
Bioassay
radioreceptor (receptor binding) assay
provocative tests

16

What is the caveat of immunological methods to measure hormones?

doesn't always correlate w biological activity since Ab binding site usually not active site

17

What is the only method for measuring hormone that gives a definitive measure of biological function?

bioasay, but difficult to run