Endocrine manipulation Flashcards
Define doping
the use and abuse of performance enhancing substances in elite sport.
Motivations for use of doping
v To enhance performance
v Higher strength, endurance, recovery, alertness, aggression, calmness, drive to win
v Lower reaction time, fatigue, anxiety, muscle tremor
v Financial incentives – prize, bonuses, endorsements,
etc.
v Belief that others are doing it too
v Coping with pain and injury rehabilitation
v Weight control
v Hide use of other drugs
Classes and effects of performance enhancing drugs
1) Stimulants: caffeine, amphetamine, cocaine
2) Build muscle/bone: hGH, IGF-1, anabolic steroids
3) Relaxants: alcohol, beta-blockers
4) Mask pain
5) Increase oxygen delivery
6) Reduce weight: diuretics (can be used to dilute the drugs present in the system)
7) mask drug use: diuretics: plasma expanders
What type of chemical is caffeine?
A Methylxanthine: purine metabolites
How does caffeine exerts its effects?
Exerts effects by:
v Increase in cAMP by inhibition of phosphodiesterase
v Translocation of Calcium for more neuro-muscular availability via a GPCR
What are the effects of caffeine? Which athletes might wanna use it
- Enhanced nervous (mood) and cardiovascular functions
- Beneficial most in endurance events, such as cycling
Is caffeine banned in sports?
- Is banned by IOC and NCAA in large doses
- Legal limit: 15 μg/ml. Equal to 6-8 cups of coffee at one sitting, with testing within 2-3 hours
Caffeine side effects
Insomnia, irritability, nervousness, tachycardia, arrhythmias and possibly death!
Medical use of beta-blockers
Reduce blood pressure, Migraine headaches, Heart arrhythmia, Alcohol withdrawal and Anxiety
How do beta-blockers act?
Which athletes would use it?
Beta Blockers block the beta receptor in cardiac muscles, thus reduce anxiety, jitters, and slows the heart rate.
Commonly used in sports that require a steady hand. v
Golf, Archery, Bowling, Pool, Biathlon, Rifle shooting etc.
What is the normal function of GH?
Normal function of GH is growth and development of every system, including bone and muscle
What are the direct and indirect ways of administering GH?
Indirect (eg. Stimulate GH axis by GHRH, vasopressin)
Direct (e.g. Inject recombinant GH or IGF)
is hGH dopping banned?
Banned by NCAA and IOC
How can agencies test of hGH use?
No urine test available (detectable in blood) but endogenous vs exogenous (?) + withdraw usage prior to games to achieve “normal” blood levels
Side effects of hGH use
Acromegaly (may be irreversible)
Peripheral Neuropathy
Coronary Artery Disease and Cardiomyopathy
Diabetes, Hypothyroidism, arthritis
What is the normal function of Erythropoietin (EPO)?
- Hormone released by the kidneys in response to low Hematocrit (blood cell volume)
- Stimulates RBC production from bone marrow
- Can increase hematocrit in renal patients by up to 35%,
lasting up to 7 months - Used in treatment of anemia
How can EPO be used by athletes?
Abused by endurance endurance athletes to increase oxygen carrying capacity by daily injection of EPO
Biological basis of blood doping
Instead of taking EPO, some athletes re-transfuse their own blood 1-7 d before an event (e.g. Tour de France)
- Induced Erythrocythemia: increases Hb following reinfusion of an athlete’s blood
- Goal: to increase the oxygen-carrying capacity of Hb
- Banned by IOC
What is the best studied type of hormone replacement therapy?
HRT for reducing symptoms associated with menopause
What are the signs of Adult manifestation of GH deficiency
Adult manifestation of GH deficiency - cardiovascular risk, reduced bone health
Is Growth hormone or IGF-1 HRT beneficial in adults
Inconsistent data on their benefits
Describe Thyroid hormone replacement therapy
hypothyroidism presents multiple
clinical symptoms
Severe cases: myxedema and coma
Levothyroxine (L-T4) replacement
