Current research suggests that the primate corpus luteum consists of subpopulations of luteal cells that differ in endocrine activity, plus other cell types that likely influence luteal cell function (Fig. 5). In addition to classical hormones, various cell types produce a number of substances that may act locally to control the development, function, and lifespan of the corpus luteum. However, many issues remain unresolved. It is important to determine whether differences between data of various laboratories are due to species differences in luteal cell subpopulations or to different methods and criteria for isolating and classifying cell types. To date, luteal cell subpopulations have been isolated exclusively on the basis of size (i.e., small and large cells). Other techniques, such as fluorescence-activated cell sorting, must be applied to isolate cell types based on their function or endocrine, paracrine, and autocrine regulation. Multiple approaches examining cell types within intact luteal tissue, as well as in preparations of dispersed, highly purified subpopulations, are needed to discern cellular origins, population dynamics, and cell-to-cell interactions. Such information is vital to understanding the processes underlying the formation and regression of the corpus luteum in the normal menstrual cycle or its further differentiation and delayed demise in early pregnancy. As attention turns to the cellular and molecular aspects of luteal function, new parameters may be available for diagnosing and treating luteal dysfunction in spontaneous or artificial cycles. It is conceivable that various types of abnormal luteal phases (e.g., the short luteal phase, the inadequate luteal phase of normal length) are related to defects in specific luteal cell types or lesions in cell types at different times during development. Analyses of luteal tissue and cells from model systems or patients with apparent luteal dysfunction (e.g., women with recurrent early abortion) could provide information on the cause and possible treatment of the disorder. As important endocrine and local roles for estrogen, inhibin-related peptides, or other luteal products are established, it may prove beneficial to provide more than progesterone supplements during luteal dysfunction to promote fertility.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Reproductive Medicine