To further investigate the relative importance of androgen receptor-mediated testosterone actions compared to estradiol effects, an increasing number of animal experiments have been published, in particular in the orchidectomized rodent, a well-characterized model for hypogonadal osteoporosis. Following orchidectomy, bone resorption increases at cancellous and endocortical surfaces and results in reduced cancellous and cortical bone volume. Periosteal bone formation during growth is decreased in orchidectomized rodents as well and further lowers bone strength [ 1 ]. A number of animal experiments have investigated the bone phenotypic changes induced by androgens, nonaromatisable androgens and estrogens in orchidectomized rodents (mice, rat and growing/non-growing). Table 3 shows the relative effects of androgens [ 32 – 34 ], non-aromatisable androgens [ 32 – 36 ], estrogens [ 33 , 36 , 37 ] on bone turnover, bone density, and periosteal bone formation in male orchidectomized rats.
Side-effects from the use of steroids are extremely common and can be quite significant. Most side-effects are reversible once the athlete stops usage although serious long-term side-effects and even death have occurred as a direct result of steroid use.
• Decreased sperm production and sex drive
• Increased aggression, irritability and mood swings
• Liver disorders
• Baldness (alopecia)
• Hypertension (high blood pressure)
• Raised cholesterol
• Gynecomastia (development of over-sized mammary glands in males)
• Menstrual irregularities (in women)
• Hirsuitism (excessive hair growth occurring in females which follows the pattern of male hair growth, . facial)
• Deepening of the voice
• Reduced immunity
• Possible development of tumors (wilm’s tumor, prostate carcinoma and leukemia have been reported, although a connection is not proven)