[Certain barrier-forming structures of the testis]

Tunica of the twisted spermatic canal is an important component of the hemato-testicular barrier ensuering a selected penetration of some substances (metabolites, hormones) from the blood bed into the "spermatogenic epithelium" and vice versa. The structure of this tunica in the male mice is not identical along the whole length of the twisted spermatic canals. The differences are connected with both number of layers, cellular and acellular, and with their distinction and, that is more essential, with differences in structure and function of myoid cells--the most important component of the peritubular tissue. The differences mentioned above demonstrate various degree of distinction of the hemato-testicular barrier along the course of the twisted spermatic canals of the mouse.