ABSTRACT
This chapter discusses the major endocrine and paracrine and autocrine mechanisms involved in the regulation of endometrial epithelial growth. Human endometrial function is primarily under endocrine control; estrogen stimulates proliferation and progesterone induces differentiation in a cyclic fashion. The effects of estrogen are predominantly seen in the outer layer of the endometrium during the follicular phase of the ovarian cycle. The growth of the endometrium also involves angiogenesis, with the formation of new capillary blood vessels from existing microvessels by sprouting. The major cellular components of the endometrium are the epithelial cells, the stromal cells, and those associated with blood vessels. Epithelial cells are classified into luminal and glandular epithelium. Endometrial stroma is composed of a heterogeneous population of cells. A great number of molecules, including growth factors, the receptors and binding proteins, cytokines, prostaglandins, adhesion molecules, membrane-bound proteases and matrix metalloproteases, are known to have paracrine functions in the human endometrium.
