title: The ultrastructure of mammary explants from virgin ovariectomized goats during hormone-induced lactogenesis.
abstract: The effect of insulin (I), cortisol (F) and prolactin (P) on the ultrastructural morphology of epithelial cells of cultured mammary explants from virgin ovariectomized (OV-X) goats were studied. The epithelial cells showed little structural organization and were devoid of fat droplets and secretory protein granules at zero time of culture. The cytoplasm contained few profiles of smooth and rough endoplasmic reticulum and the Golgi apparatus was rudimentary. After being cultured in Waymouth's medium without added hormones the epithelial cells were indistinguishable from epithelial cells of uncultured explants. The addition of I induced changes mainly in the appearance of nucleoli. The nucleoli were enlarged and fibrillogranular areas with light spaces were observed. The most obvious cytological changes of epithelial cells of explants cultured in the presence of I and F are translocation of the nucleus into the basal cytoplasm, increase of rough endoplasmic reticulum, an increase in the size of the Golgi apparatus, presence of one or two lipid droplets and in some cells vacuoles with protein granules were present. Mitochondria were more abundant. The epithelial cells of explants cultured in the presence of I, F and P were characterized by the polarization of organelles within the cytoplasm and by the formation and release of protein granules and small and large fat droplets. The cell nucleus was in the basal cytoplasm, the Golgi apparatus was supranuclear. The rough endoplasmic reticulum was extensively developed and formed large sacs. Golgi vacuoles contained protein granules.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D002369:Castration; D046508:Culture Techniques; D005260:Female; D006041:Goats; D006854:Hydrocortisone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007774:Lactation / Q000187:drug effects; D008321:Mammary Glands, Animal / Q000648:ultrastructure*; D008854:Microscopy, Electron; D011247:Pregnancy; D011388:Prolactin / Q000494:pharmacology
chemical_list: D007328:Insulin; D011388:Prolactin; D006854:Hydrocortisone