MICROVASCULATURE OF THE HUMAN TESTIS IN CORRELATION TO LEYDIG-CELLS AND SEMINIFEROUS TUBULES

The microvasculature of the human testis is closely related to the Ley dig cells and the seminiferous tubules. Semi-thin sections of testicul ar tissue serve as a basis for the computer-aided 3-D reconstruction o f the microvasculature, the seminiferous tubules and the Leydig cells. After vascular perfusion with glutaraldehyde (5.5%) and paraformaldeh yde (4%), it is possible by means of light and electron microscopy, to analyse the organization of the capillaries between the Leydig cells (inter-Leydig cell capillaries) as well as of those within the lamina propria (intramural capillaries). These arise from arterioles, derivin g from branches of the segmental arteries. The capillaries ramify betw een the Leydig cells and run either semi-circumferentially around the seminiferous tubules (peritubular capillaries) or penetrate the lamina propria of the neighbouring tubules. This is the beginning of the int ramural capillary which after leaving the tubular wall continues to a further capillary path. Consequently, the microvasculature of the huma n testis with regard to the seminiferous tubules is subdivided into af ferent, intramural and efferent capillaries. Leydig cell clusters are present on both the arterial and the venous sides of the microvasculat ure.