2Banned substances and practices Anabolic steroidsStimulantsHormone agonistsHormones and releasing factorsDiureticsBeta-2 agonistsNarcoticsBlood dopingBeta blockersGene dopingIs it an infringement of athletes human rights to be required to give blood and urine samples?Page reference: Edexcel A2 Biology (concept) textbook
3Steroid hormonesPass through the plasma membrane and stimulate protein synthesisOther steroid moleculesSteroidhormones
4Mechanism of action of steroid hormones: cell surface membraneHormone enters cell and binds with receptorComplex binds to DNA and acts as atranscription factorreceptorenters nucleusnuclearmembranehormone-receptorcomplexSwitches on a gene for synthesis of a protein
5Testosterone Stimulates protein synthesis Results in bigger and stronger muscles
6Anabolic steroidsNatural testosterone is quickly broken down. Testosterone is modified to produce drugs that remain for longer in the body These synthetic anabolic steroids are illegal.testosteronenandrolone
7Side-effects of using anabolic steroids Infertility due to disruption of normal hormone production:- disrupted menstrual cycle- reduced sperm productionimpotence In addition: - liver damage- high blood pressure- heart attacks- increased aggression21 year old body builder: A and B Severe acne conglobata C After 8 weeks off steroids and with antibiotics
8Peptide hormones Peptide hormones do not enter the cell. They bind to receptors on the cell surface membrane. They also act to switch genes on or off.Human erythropoietin
9Mechanism of action of peptide hormones: receptorcell surface membraneSecondary messenger activated: initiates a protein kinase cascadeacts as a transcription factor which switches on gene for a specific proteinInactive secondary messenger eg. cAMPenters nucleus
10Erythropoietin Erythropoietin is synthesised in the kidneys Causes the synthesis of enzymes required for synthesis of red blood cells (erythrocytes) in bone marrow. Useful for treating anaemia.
11Use of erythropoeitinIncreases number of blood cells and therefore enhances oxygen supply to muscles.Improvement of 10% in aerobic performanceUse is popular with endurance athletes and cyclists
12Side-effects of overuse of erythropoietin Excess of red blood cells can lead to strokes and heart attacks .Attacks most common at night due to low heart rate.Thought to have caused the unexpected deaths of 18 european cyclists betweenAbuse difficult to prove as it is naturally occurring.
13Ethics of performance-enhancing drugs Problems with deciding on what is illegal:Ethical questions:Creatine is not banned:Classed as a nutritional supplementCan cause kidney damage and high blood pressureIs everything acceptable in the pursuit of sporting excellence?Erythropoietin is banned:Is a naturally occurring hormoneCan cause strokes and heart attacksIsn´t it the choice of the athlete to risk using drugs or not?Blood doping banned:Donating, storing and transfusing own blood beforecompetitionDo use of performance- enhancing drugs improve or ruin competition?High altitude training not banned:Increases number of red blood cells.Caused by natural increase in erythropoietin production.Are there circumstances when drug use is acceptable?
14EssayRead pages 182 – 183 (of concept approach textbook) and answer question 2 on page 183:Describe an absolutist and a relativist ethical position on the proposal to set a maximum total red blood cell count for athlete rather than measure erythropoietin levels.