[An immunoelectron microscopic study of growth hormone secretory granules in human pituitary]

Two fetal and 8 adult pituitaries as well as 12 pituitary growth hormone (GH) cell adenomas were studied with immunoelectron microscopy using immunogold double labelling. The secretory granules in the GH cells were GH-immunoreactive, and there were no differences in size, electron density and morphology among the samples. Large, pleomorphic secretory granules were often seen in the GH cell adenomas: they were GH-immunoreactive and prolactin-negative. The authors except that double labelling with immunogold will be useful for clarifying the nature of the large, pleomorphic secretory granules.