THE STRUCTURE AND ULTRASTRUCTURE OF THE LEYDIG CELLS AND THE MYOID PERITUBULAR CELLS IN THE MINI-PIG TESTIS

Abstract

SUMMARY The morphology of the Leydig cells and of the myoid peritubular cells in the testis of the Gotting mini-pig (Sus scrofa L.) is described at the optic microscope and electron microscope levels. The Leydig cells, which are more abundant than in any other mammalian species, are large and of two types, although intermediate stages exist. Type I show a clear nucleus devoid of large eterochromatine blocks, a large cytoplasm; mitochondria with poorly developed cristae are packed in the centre of the cell. The SER, with enlarged tubules and vesicles, is well developed at the periphery of the cell. The RER is scanty. Type II cells show a nucleus richer in eterochromatin, mitochondria equipped with many tubular cristae and more scattered, a SER made up of narrow tubules and a more abundant RER. The Δ-5-3-β-HSDII reaction is strongly positive in all the cells. The two cellular types probably correspond to different functional stages. The seminiferous tubule wall appears to be formed by a double connective la...