Estradiol-induced mitogen-activated protein kinase (extracellular signal-regulated kinase 1 and 2) activity in the frog (Rana esculenta) testis.
Several lines of evidence support a key role of estradiol-17beta (E(2)) in male fertility. We have used a non-mammalian vertebrate model, the frog Rana esculenta, to investigate the regulation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) activity in the testis during the annual sexual cycle and to study whether E(2 )exerts a role in spermatogenesis through the regulation of ERK1/2 activity. ERK1/2 proteins are present in the cytoplasm and nucleus of the primary and secondary spermatogonia (SPG), and in the nucleus of primary spermatocytes. The annual E(2) profile shows a progressive increase during active spermatogenesis with a peak in the month of June. In parallel, ERK1/2 are highly phosphorylated during the period of active spermatogenesis (from April to July) compared with the regressive period (September/October) and winter stasis (from November to March). E(2) treatment induces the proliferation of primary SPG, possibly via the activation of ERK1/2, and this effect is counteracted by the anti-estrogen ICI 182-780.
Chieffi
P
P
Dipartimento di Fisiologia Umana e Funzioni Biologiche Integrate 'F. Bottazzi' II, Università di Napoli, Naples, Italy. Paolo.Chieffi@unina2.it
Colucci-D'Amato
G L
GL
Staibano
S
S
Franco
R
R
Tramontano
D
D
D000818:Animals; D004958:Estradiol / Q000097:blood / Q000494:pharmacology* / Q000502:physiology; D007124:Immunoenzyme Techniques; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism*; D010766:Phosphorylation; D011893:Rana esculenta; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D013091:Spermatogenesis / Q000187:drug effects; D013737:Testis / Q000201:enzymology*
D004958:Estradiol; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases