Peritubular cell influence on the efficiency of androgen-binding protein secretion by Sertoli cells in culture

The efficiency of androgen-binding protein (ABP) secretion into the medium of cultured Sertoli cells was increased by the addition of peritubular cells into the culture system. There was a positive correlation between the number of peritubular cells added to the cultures and the amount of ABP secreted. These responses were observed in cultures treated with highly purified FSH or in untreated cultures. Medium that had been exposed to peritubular cells before exposure to Sertoli cells did not mimic the effect observed when peritubular cells were added directly to Sertoli cells. The efficiency of ABP secretion by Sertoli cells was not a function of plating density, since the amount of ABP per mg cellular protein did not vary significantly among cultures of Sertoli cells which contained a wide variation in the numbers of cells present. These results suggest that peritubular cells play a role in regulating ABP secretion and thus support the hypothesis that cell to cell communication exists between these two cell types of the seminiferous tubule.