Ultrastructural changes induced by oestradiol-17β, progesterone and oestrone-3-sulphate in guinea-pig endometrial glandular cells grown in primary culture

Abstract

ABSTRACT The effects of oestradiol-17β, progesterone and oestrone-3-sulphate were studied in primary cultures of guinea-pig endometrial glandular epithelial cells. Comparative ultrastructural studies were performed by means of transmission electron microscopy on cells grown either without hormones or with oestradiol-17β (2 nmol/l), oestradiol-17β (2 nmol/l) plus progesterone (50 nmol/l), or oestrone sulphate (0·1 μmol/l). In the control medium, without steroid hormones, the majority of epithelial cells were poorly differentiated, although numerous small mitochondria were present and abundant lipid droplets could be observed. Oestradiol-17β stimulated metabolic activity in the cells. Progesterone added to oestradiol-17β-primed cells stimulated the development of the endoplasmic reticulum–Golgi system. Oestrone sulphate induced a higher level of differentiation characterized by large clear mitochondria, well-developed Golgi complexes, and active nuclei, suggesting secretory activity. In all cases, the cultured cells displayed deep invaginations of the nuclear membrane associated with nuclear pores, known as nucleolar channels. After treatment with oestrone sulphate these channels were associated with a characteristic reticular nucleolus. We conclude that cultured endometrial epithelial cells display secretory activity in response to treatment with oestradiol-17β plus progesterone, or with oestrone sulphate. Journal of Endocrinology (1989) 122, 439–444