While it has been shown that culture medium from testicular macrophages can influence
testosterone production when added to Leydig cells, the identity of the factor (s) responsible
for this activity remains unknown. Since tumor necrosis factor α (TNFα) has been shown to
be capable of influencing testosterone production by Leydig cells, a series of studies was
conducted to determine if testicular macrophages produce TNFα. It was found that testicular
macrophages from adult rats produce a factor that is capable of lysing L929 cells, which are …