... of this axis to endocrine stimulation. Here, we present data from an experiment in Abert's towhees, Melozone aberti , using gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) challenges to investigate whether energy deficiency modulates the plasma testosterone responsiveness of the HPG axis...

... testosterone increased in response to photostimulation in ad libitum -fed but not in food-restricted birds. Food availability did not, however, affect the plasma testosterone increase resulting from a gonadotropin-releasing hormone-I (GnRH) or a luteinizing hormone (LH) challenge. The number of hypothalamic...

... of plasma luteinizing hormone (LH) at regular intervals to monitor changes in reproductive function. The onset of egg laying was not advanced by the presence of leafing branches and caterpillars. LH concentrations increased during the course of the study, but phenological cues did not affect plasma LH...

...-mail: [email protected] ) 14 10 2008 2009 spawning migration salmon follicle-stimulating hormone luteinizing hormone steroid hormone pituitary–gonadal axis The spawning migration of chum salmon is an annual reproductive behavior that covers thousands of miles ( Salo,1991...