Testicular atrophy caused by steroids

Dejager et al. (2002) performed detailed endocrine investigations in 22 men with Kennedy disease. Clinical signs of partial androgen resistance were present in more than 80% of the patients, with gynecomastia being the most prominent. Thirteen patients had alteration of testicular exocrine function. Hormonal profile of partial androgen resistance was present in 86% of the patients, with an elevated testosterone level in 68%. Dejager et al. (2002) noted that androgen insensitivity seems to appear later in life in Kennedy disease, similar to the development of neurologic signs. The authors stated that in clinical practice, Kennedy disease patients are often misdiagnosed as having ALS, and that careful examination of the endocrine component could avoid such a deleterious misdiagnosis.

During aging, there is a gradual decrease in the ability to maintain skeletal muscle function and mass. This condition is called " sarcopenia ", and may be distinct from atrophy in its pathophysiology. While the exact cause of sarcopenia is unknown, it may be induced by a combination of a gradual failure in the " satellite cells " which help to regenerate skeletal muscle fibers, and a decrease in sensitivity to or the availability of critical secreted growth factors which are necessary to maintain muscle mass and satellite cell survival. [2]

2) Irreversible adaptation to sperm competition . It has been suggested that the ancestor of the boreoeutherian mammals was a small mammal that required very large testes (perhaps rather like those of a hamster ) for sperm competition and thus had to place its testes outside the body. [44] This led to enzymes involved in spermatogenesis, spermatogenic DNA polymerase beta and recombinase activities evolving a unique temperature optimum, slightly less than core body temperature. When the boreoeutherian mammals then diversified into forms that were larger and/or did not require intense sperm competition they still produced enzymes that operated best at cooler temperatures and had to keep their testes outside the body. This position is made less parsimonious by the fact that the kangaroo , a non-boreoeutherian mammal, has external testicles. The ancestors of kangaroos might, separately from boreotherian mammals, have also been subject to heavy sperm competition and thus developed external testes, however, kangaroo external testes are suggestive of a possible adaptive function for external testes in large animals.

Testicular atrophy caused by steroids

testicular atrophy caused by steroids


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