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ON TESTIS AND EPlDlDYMlS OF RATS - Pondicherry University ...

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lysosome, peroxisome and number of lipid droplets (for review, see Johnson e! ul..<br />

1999). Leydig cells are associated with blood vessels (Fawcett et 01.. 1973) or found<br />

nearer to the walls of the seminiferous tubules (Bergh, 1983). The presences of mast<br />

cells and macrophages have been reported in the interstitial compartment (Nistal el<br />

a/., 1984; Christensen et 01.. 1985). Sertoli cells are found immediately inside the<br />

boundary tissue of the seminiferous tubular and surrounded by undeveloped germ<br />

cells before puberty. The interstitial and seminiferous tubules compartments are not<br />

only structurally distinct but are also separated physiologically by cellular barrier,<br />

which develop during puberty and limit the free exchange of water-soluble materials<br />

(Johnson and Everitt, 1995). The plasma membranes of Sertoli cells and tight<br />

junctions between adjacent cells create adluminal compartment of the blood-testis<br />

barrier. Sertoli cells share the surface of the boundary tissue with the developing<br />

spermatogonia (Fawcett, 1975). Sertoli cells have intricate cytoskeleton and<br />

numerous processes, which are responsible for positioning, movement and shaping of<br />

the spermatogenic cells. Occluding junction between adjacent Senoli cells prevent<br />

free exchange of molecules from outside of the tubule into the spermatocytes a~d<br />

spermatids (de Kretser er ol., 1995). Sertoli cells have been reported to perform large<br />

number of specific functions including secretion of fluid, phagocytosis, maturation,<br />

release of spermatozoa and synthesis of intratubular androgen binding prorein<br />

(Chemes, 1986; Clermont el al. 1987).<br />

Spermatogenesis is the process of gradual transformation of germ cells into<br />

spermatozoa over an extended period of time within the boundaries of thc<br />

seminiferous tubules of testis. This process involves cellular proliferation by repeated<br />

mitotic divisions. duplication of chromosomes. genetic recombination through<br />

crossover and reduction division by meiosis to produce haploid spermatids, and<br />

terminal differentiation of sperrnatids into spermatozoa (for review, see de Kretser r/<br />

ul.. 2000). Seminiferous tubules contain a large n~rmber of germinal epithelial cells<br />

called spermatogonia, located in two to three layers along the outer border of the

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