Control of GnRH secretion.

During a discussion at the 1st International Symposium on Reproduction in Domestic Ruminants following Dr Gerald Lincoln's presentation, it became apparent that we needed a method to monitor gonadotrophin-releasing hormone (GnRH) secretion in sheep. Within the 6 years that have elapsed, three models have been developed for this purpose and it is now possible to monitor accurately the secretion of GnRH from the median eminence and to relate this to LH and FSH release We arc therefore able to conduct meaningful experiments to ascertain the roles of the various neural systems and feedback effects that might regulate GnRI-1 secretion. This paper will review the progress that has been made in measuring the secretion of GnRH, particularly in sheep, and consider steroidal feedback effects. Finally, brief consideration will be given to some of the various neural systems that might be involved in regulating GnRH secretion.