Cytochemical studies of multifunctional gonadotropes.

Studies have focused on the roles of the gonadotrope subsets defined by cytochemical and morphological tools. The evidence points to groups of gonadotropes that may be stimulated to mature and secrete to support surge activity. We postulate that these gonadotropes stem from the medium-sized subset. Other gonadotropes may more involved with maintenance functions. Perhaps these come from the larger cell pools. Monohormonal gonadotropes may play unique roles, such as FSH secretion early in estrus. Some may be immature, others may be regulatory and play both paracrine or autocrine roles in the pituitary cell population. We also recognize that one of the limitations of the current-day cytochemical techniques is that it does not define the entire gonadotrope population in any given two-label protocol. Nevertheless, based on past cytochemical studies, assumptions are made about the extent to which the cells express both hormones or behave in a uniform manner. These assumptions have led researchers to focus on one subset of the gonadotrope population. In their attempts to simplify the population to be studied, they may have eliminated important regulatory, secretory, or monohormonal gonadotropes from the pool. The approach is valid, as long as they recognize that they are studying a subset of a complex and dynamic population.