Effects of Osteocalcin on Synthesis of Testosterone and INSL3 during Adult Leydig Cell Differentiation

Figure 9

Electron microscopic view of testicular tissue samples of postnatal subjects (Group 1). (a) Membrane propria (MP), Sertoli cells (S), spermatocytes (Spt), spermatids (Spd), and nucleus (N) were seen to be normal in control subjects (Group 1A). Tight connections between the Sertoli cells (arrowhead) were observed as normal like the cytoplasmic bridges (arrows) between the spermatogenic cells. Leydig cells (LC) were seen to have normal tubular-type mitochondria (M) and abundant lipid droplets (L) in their cytoplasm. SER: agranular endoplasmic reticulum; bar = 2 μm. (b) Thick and curved membrane propria (MP) and Sertoli cells (S) containing excessive and abnormal vacuolization (V) were indicated in GnRH-antagonist-administered subjects of Group 1 (Group 1B). My: myoid cells. (c) A decrease in the cytoplasmic volumes of some Leydig cells (LC) and an increase in the peripheral heterochromatin patches in the nucleus (N) were seen in testicular tissue samples of Group 1B. In the cytoplasm of some Leydig cells (LC), low electron density, dense agranular endoplasmic reticulum (SER) vacuolization, and intact mitochondria (M) were noted. Bar = 0.5 μm. (d) Relatively reduced curvature and thickness in the membrane propria (MP) were observed. Giant vacuoles (V) between Sertoli cells (S) and relatively normal spermatocytes (Spt) were seen in GnRH-antagonist-and-osteocalcin-administered subjects of Group 1 (Group 1C). (e) Decreased cytoplasmic volume in Leydig cells (LC) showed an increase in indentation and a decrease in heterochromatin content of the nucleus (N) in testicular tissue samples of Group 1C. In the cytoplasm, it was noted that agranular endoplasmic reticulum (SER) seemed to have vacuolization, but mitochondria (M) remained intact. Bar = 0.5 μm. (f) Sertoli cells (S) and spermatocytes (Spt) were also found to be normal in seminiferous tubules surrounded by normal membrane propria (MP) in only-osteocalcin-administered subjects of Group 1 (Group 1D). The tight junctions between the Sertoli cells (arrowhead) were normal. Ls: lysosome; bar = 1 μm. (g) Increased lipid droplets (L) were observed in the cytoplasm of the Leydig cells (LC), which have decreased heterochromatin content and indentation in the nuclei (N) of testicular tissue samples of Group 1D. Cap: capillary; bar = 1 μm.