Designer Anabolic Agents: Safety and Efficacy

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Transcript Designer Anabolic Agents: Safety and Efficacy

Designer Anabolic/
Anti-catabolic Agents
Lecture 21
What works?
• We know that:
– Anabolic steroids (testosterone) increase FFM
and muscular strength. They also have an anticatabolic effect.
• Schedule III drug available legally with a prescription
– Prohormones (androstenedione and
androstenediol) have some (maybe) effect
increasing FFM or strength performance.
– Sale of androstenedione and androstenediol (but
not DHEA) restricted by U.S. govt. in late 2005
What works?
• We know that:
– Anabolic steroids (testosterone) increase FFM
and muscular strength. They also have an anticatabolic effect.
• Prohormones (androstenedione and androstenediol)
have no apparent effect on increasing FFM or
strength performance.
– Creatine - will be talking about creatine on
Wednesday)
• Are there other products that work to
increase FFM, strength and power?
– Anabolic (growth hormone secretagogues)
– Anti-catabolic (inhibitors of protein degradation)
Popular “Body Building” Supplements
Anabolic:
• Growth Hormone secretagogues
• Zinc/Magnesium Aspartate (ZMA)
• Arginine alpha-ketoglutarate (AAKG)
Anti-catabolics:
• Beta-hydroxy beta-methylbutyrate (HMB)
Growth hormone (somatotropin)
– Stimulates bone and cartilage growth
– Facilitates protein synthesis
• Increasing amino acid transport into muscle
• Stimulating RNA formation
• Facilitating protein synthesis
– Also slows CHO breakdown and mobilizes fat
as an energy source.
Exercise stimulates an increase in circulating GH
and preserves plasma glucose for the CNS.
Growth Hormone: Ergogenic Aid
• Use medically, children who suffer from GH
deficiencies or kidney failure
– Reduced GH: low FFM and high fat mass
– Increased GH in youth: gigantism
• Acromegaly – enlarged hands, feet and facial
features.
• Synthetic growth hormone (recombinant
DNA production) is used by athletes and
bodybuilders to increase strength
performance.
Growth Hormone: Performance
• Appealing to strength and power athletes
because at physiological levels:
– Stimulates amino acid uptake and protein
synthesis
– Enhances fat breakdown
– Conserves glycogen reserves
Also GH does not suppress the body's
hypothalamic-pituitary-gonadal axis like
anabolic steroids. Use can be continuous.
One study found that 6 weeks of resistance
training with GH decreased body fat and increased
FFM significantly (but second study found no effect).
GH is illegal and very expensive. The hormone
can only be obtained on the black market and can
cost $500-4000/month.
GH is usually stacked with anabolic steroids and is
typically used with insulin to get maximum results.
Body-builders use the combination to achieve the
desired muscle size, vascularity and appearance of
paper thin skin “sucked to muscle”.
**** Growth hormone use can lead to diabetes
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Growth hormone secretagogues
• Use of amino acids to stimulate GH
secretion.
– Arginine
– Lysine
– Ornithine
Exercise increases GH concentrations so these
amino acids are often taken before a workout to
further accentuate the exercise-induced GH release.
• Amino acid ingestion and GH
– Combination of arginine and lysine together seems to
be more potent than either alone.
– Trained individuals have a blunted response (especially
if they are strength trained eating a high protein diet)
– Women show a greater response than men
• Amino acid ingestion, GH and exercise
– Ingestion of amino acids before exercise does not
increase GH more than exercise alone.
– Consuming a protein supplement before exercise and
immediately after exercise had no effect on maintaining
elevated GH concentrations.
• May be a dosage or timing issue, further studies
necessary... There are no well-designed studies
using specific amino acids as GH secretagogues
in conjunction with strength training.
• Alternatively, peptide and non-peptide compounds
can also stimulate GH release.
– Ex: synthetic hexapeptide (GHRP-6)
These secretagogues do increase circulating GH and IGF1, there are no published studies indicating how use
would affect athletic performance.
Zinc/Magnesium Aspartate (ZMA)
• Popular supplement to promote anabolism
at night.
– Zinc/magnesium deficiencies may reduce the
production of testosterone and IGF-1 (regulates
the action of GH)
– Shown that athletes in training may be zinc
deficient. Zinc participates in metabolism and
protection against free radical damage.
– Magnesium supplementation showed a
decrease in cortisol (theoretically magnesium
would be anti-catabolic).
• Studies:
– Brilla and Conte reported ZMA supplementation
in football players during off-season resistance
training promoted increases in testosterone,
IGF-1 and muscular strength.
– Wilborn et al. (2004) double blind study design
• n=42 resistance trained males
• matched according to FFM
• Took either ZMA or placebo prior to going to sleep
during 8 weeks of strength training
Results: no significant differences between
groups in hormone status, body comp, 1 RM
bench press and leg press, muscular endurance
or anaerobic capacity.
- population was resistance trained.
Arginine alpha-ketoglutarate (AAKG)
• Anabolic and anti-catabolic
Arginine:
1. stimulates GH release
2. Raises nitric oxide (NO) synthesis
– NO acts as a vasodilator. Hypothesized that NO
supplementation would enhance blood flow, oxygen
delivery and glucose uptake by working muscles.
α-ketoglutarate:
- Intermediate in the TCA cycle and is a precursor
for the synthesis of glutamine and arginine.
- Limited data on athletic performance; however,
there is some data that suggests an anticatabolic role. (similar to glutamine under
conditions over severe stress, ex: surgery)
• Campbell et al. (2006)
– Randomized, double-blind, controlled study
design
– 12g daily (4g, 3X per day) over 8 weeks of
resistance training (4X per week)
– Measures were taken at 0, 4, 8 weeks in blood
markers, 1 RM max strength, aerobic power,
anaerobic endurance, total body water and
body composition.
Beta-hydroxy beta-methylbutyrate (HMB)
• HMB is a metabolite of the amino acid leucine.
– Found naturally in small quantities in catfish, citrus fruits
and breast milk.
– Leucine is an essential amino acid that has the highest
oxidation rate of all amino acids during exercise.
HMB derived from leucine is converted to HMG-CoA in
some tissues and serves as a key carbon source for
cholesterol synthesis in various cell types.
- saturating the cell with HMG-CoA would allow the cell
to undergo the maximum growth response (athletes,
muscle hypertrophy in response to resistance training)
• Supplementing with 1.5-3g/d of calcium
HMB has demonstrated increases in muscle
mass and strength (especially in untrained
individuals initiating a training program)
– Gains are typically 0.5 to 1kg greater than
controls during 3-6 weeks of training.
• Also evidence that HMB is anti-catabolic.
HMB in conjunction with creatine may have
an additive effect but results are unclear.
•
– Large variability among athletes, more research
is necessary.
Please check the website for a reading on
tetrahydrogestrinone (THG), the designer
anabolic steroid that BALCO constructed in
2002-2003.