Abstract
Pituitaries from castrated male mice injected with cyproterone acetate were examined ultra-structurally. LH gonadotrophs showed two types: (a) those containing a dilated RER, a hypertrophied Golgi, and decreased granular content; and (b) those presenting an electron leucent cytoplasm and a nonhypertrophied RER. Following cyproterone acetate treatment both LH cell types showed increased RER cisternal hypertrophy and absence of Golgi membranes. In LH type (a) gonadotroph-increased granular content was noted. No detectable alterations were noted in FSH gonadotrophs following cyproterone acetate treatment. Cyproterone acetate may have stimulated the synthesis of the protein component but inhibited the incorporation of the carbohydrate moiety and LH release.