MAEKAWA Mamiko Chiba University, School of Medicine, Department of Anatomy. Assistant., 医学部, 助手 (20181571)
TOYOTA Fumie Chiba University, School of Medicine, Department of Anatomy. Associated Professo, 医学部, 助教授 (60009751)
|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1995 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1994 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Peritubular myoid cells, surrounding the seminiferous tubule have been found in all mammalian species, but their organization varies by species. In laboratory rodents, only one layr of myoid cells is seen. The cells are joined by junctional complexes as are epithelial cells. On the other hand, several cellular layrs exist in the lamina propria of the seminiferous tubule in the human and some other animals. Myoid cells contain abundant actin filaments which are distributed in the cytoplasm in a species-specific manner. In the rat, the filaments within one myoid cell run both longitudinally and circularly to the long axis of the tubule, exhibiting a latice-work pattern. The arrangement of the filaments changes during postnatal development, and the disruption of spermatogenesis, such as cryptorchidism, seems to affect the arrangement of the filaments.
Other cytoskeletal proteins, including myosin desmin, actinin, are also found in the cells. Myoid cells have been shown to be contractile, involed in the transport of spermatozoa and testicular fluid. It has been reported that biological active substances, prostaglandins, TGF,androgen receptors are known to affec the myoid cells. It is now evident that the myoid cells not only provide structural integrity to the tubule but take part in the regulation of spermatogenesis and testicular function.
In human, myofibroblasts in the lamina propria are large, flat individual cells branched in a network of microfibrils and collagen fibrils in the tubular wall. They are arranged in discontinuous cell layrs with interposed layrs of extracellular matrix. They express both antigens of smooth muscle cells and of connective tissue cells. Our experiments indicate that the contractility of myofibroblasts of men may be in part modulated by the NO/cGMP-system.