Abstract
In male rats, luteinizing hormone (LH) rises quickly within 8 hr of castration; however, in females, there is no significant increase for several days. These differences cannot be explained by sex steroid milieu, sex differences in pituitary LH content, or gender differences in LH response to gonadotropin-releasing hormone (GnRH) dose. This chapter presents a study to demonstrate that gonadectomy produces sex differences in pituitary sensitivity to different GnRH pulse frequencies and/or hypothalamic GnRH releasability, resulting in a strong sex difference in serum LH rise. The increase in in vivo GnRH pulse frequency to 1.3 pulses/hr following castration in male rats and the increased LH pulse frequency in ovariectomized female rat suggested that weak sex differences in LH release at GnRH frequencies slower than 1 pulse/hr are not relevant to sex differences in serum LH postgonadectomy. The lack of sex differences at the pituitary level and the drop in NMA-stimulated GnRH release following gonadectomy by female, but not male, median eminence suggests that the hypothalamus plays a greater role than the pituitary in regulating sex differences in LH release postgonadectomy.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
