Sertoli cell ultrastructure. II. Morphological effects of hypophysectomy in pubescent pigs

Summary. As in normal animals, the Sertoli cell population in pubescent pigs was composed of two morphological cell types : numerous cells with a light nucleus (type A) and some small cells with a dark nucleus (type B). This report studies the transformations occurring in this population during the 4 months following hypophysectomy. The various cellular components had different rhythms of modification ; no general, continuous involution of the components was observed. The nucleolar complex appearing in the nucleus was composed of three elements and persisted during the whole period studied. The majo-rity of A-cell cytoplasmic components disappeared during the post-operative period, except for some lysosomes which developed and the Golgi apparatus which persisted. The cellular junctions between Sertoli cells and those facing the remaining germ cells were unmodified. Three or 4 months after hypophysectomy, the whole of the membranous and ribosomal systems was reorganized and developed. Microtubules and microfilaments gradually disappeared. In some cases the specialized inter-Sertoli cell junctions lost their microfilamentary component. The B-cells had an extremely condensed aspect 1 month after hypophysectomy. Three or 4 months after the operation, cytoplasmic ramifications and the presence of numerous ribosomes apparently indicated a change in B-cell metabolism. The microfilaments disappeared gradually. In both cell types, the large lipid droplet persisted ; it was always found against the nucleus and often in a basal position.