Lecture 24 Flashcards
What is an anabolic agent?
A chemical agent that promotes muscle growth.
What is an ergogenic aid?
Something that allows the body to train/perform at a higher level.
What are some examples of anabolic agents?
Anabolic androgenic steroids
Growth hormone
IGF-1
Beta 2 agonists
What is the effect of testosterone on muscles?
Testosterone stimulates muscle protein synthesis and promotes bone and muscle growth
How does testosterone level change with age in mice? What happens in humans?
Older male mice have less testosterone and opposite is true for male. Same thing is seen in humans.
What does testosterone do in hypogonadal men or men with HIV and low serum testosterone?
Testosterone levels have been shown to counteract loss of lean body mass in hypogonadal men, in older men with normal or low serum testosterone, and HIV infected men with low serum testosterone.
What was the result of injecting supraphysiological testosterone to young, healthy men, and HIV infected women?
Muscle growth was acheived in eugonadal states after supraphysiological administration was given to young, healthy men, as well as HIV-infected men with normal testosterone levels, and even
How do anabolic steroids increase muscle growth?
Action can be direct or indirect;
Directly: Acting directly on the androgen receptor.
Indirectly: Modulating a gene or altering secretion of other hormones that suppress muscle growth.
Where can androgen receptors be found?
in skeletal muscles
How do androgen receptors respond to increased activation?
Increase in muscle protein synthesis and in turn increase in muscle mass
What are some beneficial effects of testosterone?
Muscle hypertrophy
Calcium deposition in bone
Lipolysis: Increase in lean body mass.
Increasing red blood cell
Motivation
What are the side effects of testosterone abuse?
Liver dysfunction
Testicular atrophy
Increase in body hair
Male pattern baldness
gynaecomastia (male breast growth)
acne
Reduced HDL cholesterol
What is the effect of injecting GH in the body?
Stimulates IGF-1 which has the following effects:
Increases fat burning
Increases lean body mass
Increases bone growth
How is GH usually taken?
GH is typically cycled with androgens or somatomedins (IGF-1)
What causes GH production in healthy people? How does the body produce GH?
GH is naturally stimulated by exercise.
GH is a natural substance released in a pulsatile manner by the body.
What are the side effects of using GH?
gigantism (pre-puberty)
acromegaly (post pubert) (enlargement of organs and growth plates start to grow)
Hypertension (increase in Na reabsorbtion)
Collagen deposition
Does GH improve strength? Can it be used therapeutically?
Improves muscle strength
Numerous side-effects and limited therapeutic potential.
What is IGF-1?
IGF-1 has a structural homology to insulin and is involved in normal growth and repair of muscle. It is closely linked to GH.
What does IGF-1 do when it binds to a receptor?
Increases protein synthesis.
Decreases protein degradation.
Increases muscle mass
Increases oxidative capacity of muscle
Can IGF-1 cause cancer?
IGF-1 has been shown to assist growth of existing tumours but it doesn’t cause tumours
What are beta agonists?
Beta agnonists are used as bronchodilators for treating asthma and have been found to have powerful effects on muscle when injected systemically and have potential to reverse muscle atrophy.
What are the effects of beta agonists?
Increase muscle mass
Increase muscle fiber size
Increase absolute force producing capacity
Cause slow to fast muscle fiber transitions
Enhance muscle repair after damage
What is the problem with using clenbuterol?
Chronically clenbuterol’s effect stalls with time and the beta adrenoceptors get less sensitive and the receptor gets downregulated after activation.
What are the problems with giving livestock clenbuterol?
If livestock are given clenbuterol the meat would also contain clenbuterol.
What are the harmful effects of beta-agonists?
Muscle tremors
Peripheral vasodilation
Cardiac hypertrophy
How can the negative side-effects of beta agonists be decreased?
Choosing a less harmful beta agonist.
Using safer doses
Treating in shorter cycles
Administering in different methods of administration
