What do interstitial cells between seminiferous tubules produce?

Interstitial cells, also known as Leydig cells, are located in the spaces between the seminiferous tubules of the testes. They play a crucial role in the male reproductive system by producing testosterone, which is essential for the development of male secondary sexual characteristics, spermatogenesis, and the overall regulation of male reproductive functions. Testosterone is a steroid hormone that has various functions, including the promotion of muscle and bone mass, the development of facial and body hair, and the maintenance of libido.

This makes testosterone the correct answer for what interstitial cells produce, as it highlights their vital role in male hormone production and reproductive health. Understanding the specific contributions of these cells helps clarify how hormonal balance and sexual maturity are achieved in males.