title: Plasma and testicular estradiol and plasma androgen profile in the male frog Rana esculenta during the annual cycle.
abstract: Seasonal plasma and testicular estradiol levels were measured in the male frogs, Rana esculenta, by radioimmunoassay. In plasma samples a simultaneous measurement of androgens was carried out in order to investigate a possible relationship between androgens and estradiol-17 beta. Concomitantly with the estradiol-17 beta peak in plasma and testes during the April-May period, plasma androgens sharply decreased.
mesh_terms: D000728:Androgens / Q000097:blood; D000818:Animals; D004958:Estradiol / Q000097:blood / Q000378:metabolism*; D008297:Male; D011893:Rana esculenta / Q000502:physiology*; D012621:Seasons; D013737:Testis / Q000502:physiology
chemical_list: D000728:Androgens; D004958:Estradiol