Exam 1 - Performance Enhancing Drugs Flashcards
(31 cards)
The effects of anabolic steroids are generally characterized by —-, while the effects of androgenic steroids are characterized by ——.
anabolic - strength and endurance
androgenic - masculinization (libido, acne, facial hair, growth of prostate, and deepening of voice)
Describe the setup and results of the exogenous testosterone muscle size/strength study.
4 groups - placebo and testosterone for both an exercise and no exercise group
testosterone increases muscle area and strength with or without exercise
combination of both testosterone and exercise gives greatest increase in muscle area and strength
People taking a higher dose of exogenous testosterone will have —– sperm concentrations.
lower
What is the basic steroid molecular structure?
A B C and D rings, with all being 6 carbon except for D, which is a 5 carbon ring
Carbons numbered 1-17, with 17 at the top of the D ring
Describe the structure and groups of a testosterone molecule
testosterone has A B C and D rings
Carbons 18 and 19 are methyl groups off of carbon 10 and 13
There is an OH and H on carbon 17
There is a =O on carbon 3
There is a double bond between carbon 4 and 5 of ring A
What kinds of structural modifications to testosterone can be used for synthetic steroids?
modify A and B rings to maximize anabolic activity and minimize androgenic activity
modify 17 carbon to determine oral or depot delivery
- 17 a-alkyl group confers oral activity by preventing deactivation by the gut or liver (first pass metabolism)
- esterification of 17 carbon confers activity for depot delivery (because it takes time for the ester group to be cleaved off and make the active form)
What are some routes of steroid drug administration?
oral (subject to first pass effect)
injection (subcutaneous or intramuscular)
pellet implant
transdermal (gel or patch)
sublingual troche
nasal spray
intra-vaginal
suppositories
What is the first pass effect/first pass metabolism?
drug metabolism where the concentration of the drug is greatly reduced before it reaches the systemic circulation
What are the 4 potential systems involved in first-pass metabolism?
gut wall enzymes
gastrointestinal lumen enzymes
bacterial enzymes
hepatic enzymes
How is a oral drug carried through the digestive system (vessels), and where does the concentration decrease?
enters the stomach at 100%, gut wall/gastrointestinal lumen/bacterial enzymes reduce to 70% which enters the hepatic portal vein, carries to liver where hepatic enzymes reduce it to 15%, and the hepatic vein carries that 15% into the systemic circulation
What vessels enter and exit the liver?
hepatic portal vein enters the liver from the digestive tract
hepatic vein enters the systemic circulation from the liver
Non-oral routes of administration are good because they…
Avoid first-pass metabolism and allow drugs to be absorbed directly into the systemic circulation
What structural modification happens to the testosterone molecule when it is converted to DHT?
The double bond is broken and a hydrogen is added on instead (there is no double bond between carbon 4 and 5)
Does testosterone or DHT have a greater affinity for androgen receptors?
DHT
How is the structure of nandrolone different from testosterone? What effect does this cause?
No 19 carbon (methyl group) on carbon 10
Greater affinity for androgen receptors than testosterone (more anabolic response)
How is the structure of 5a-dehydro-19-nortestosterone different from DHT? What effects does this cause?
No 19 carbon (methyl group) on carbon 10
Lesser affinity for androgen receptors than DHT, so decreased androgenic response
Is myotrophic similar to anabolic or androgenic?
Anabolic
In the myotrophic-androgenic index study, what were they measuring? What were each of those measures supposed to indicate?
Levator ani muscle - anabolic/myotrophic target
Prostate gland - androgenic target
Describe the Hershberger Bioassay
Immature, castrated male rats
Given a steroid of interest or a reference steroid via injection or oral gavage
Dosed every 24 h for 10 days
Animals sacrificed and levator ani/prostate are measured
How is the myotrophic and androgenic activity calculated?
Myotrophic activity = increase in levator ani weight with steroid of interest / increase in levator ani weight with control steroid
Androgenic activity = increase in prostate weight with steroid of interest / increase in prostate weight with control steroid
How is index value calculated?
Myotrophic activity / androgenic activity
What does a high index value indicate?
Higher anabolic affects with lower androgenic effects (which is preferred)
Can anabolic effects ever be completely separated from androgenic effects?
No, but some synthetic steroids present large index values with a high dissociation between the two
What are adverse effects on bone, breast, cardiovascular, and nervous systems from anabolic androgenic steroid use?
Bone - premature closure of epiphysis in children
Breast - T converted to E cause gynecomastia in males
Cardiovascular - increase risk for myocardial infarction, stroke, raised LDL and lowered HDL
Central Nervous System - increased aggression