Testicular concentrations of testosterone are approximately how many times higher than concentrations in the general circulation?

1. Leydig cells manufacture testosterone locally within the testes through a process called testicular steroidogenesis. 2. This local concentration is needed to sustain spermatogenesis at a much higher level than the body needs systemically. 3. This local-to-systemic ratio is deliberately very large. 4. 2 times and 10 times are both different figures a reader might guess from memory, but neither matches the specific figure given here. 5. 1000 times is also incorrect for the same reason: it does not match the specific figure given here. 6. That ratio is 100 times higher in the testes than in general circulation. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 27 "The Reproductive System", p.1289 §Functions of Testosterone_