Structural changes in gonadotropin-producing cells of male frogs, Rana nigromaculata, in the process of sexual maturation

Abstract

Changes in the number, size, and structure of gonadotropin-producing cells, called basophil type 2 cells, were evaluated by light and electron microscopy throughout the process of sexual maturation in second-year male frogs, Rana nigromaculata. Hyperfunctional conditions were recognized two times, in the middle of May, and in and after August. The former activation corresponded well with the start of spermatogenesis, and the latter accompanied the increasing activity of the interstitial cells. Whether or not the hormone secreted during these two periods was the same substance is discussed.