Kisspeptin-10, a hormone in the brain that is crucial to fertility, presents differently in men and women, according to data presented at the Society for Endocrinology BES 2012 meeting.
“We know very little about what its role is in the brain, in terms of controlling human fertility,” Channa Jayasena, MD, PhD, researcher and clinical lecturer at Imperial College London, told Endocrine Today. “Our hope is that by understanding and learning more about it, we can learn more about how it might be able to help people who have infertility in the future.”
Jayasena and colleagues compared the effects of kisspeptin-10 administration on gonadotropin release in healthy men and women. They administered IV bolus injections of kisspeptin-10 to men and women (four to five injections per group); women also received both subcutaneous bolus and IV infusion (four to five injections per group). The researchers collected blood samples at regular time periods for 4 hours after injection to measure plasma luteinizing hormone (LH) levels.
They observed in healthy men that IV bolus kisspeptin-10 (0.3 nmol/kg) stimulated secretion of LH, with maximal stimulation witnessed after 10 nmol/kg kisspeptin-10 (mean area under the curve LH increase: 6.1 IU/L; P<.001 vs. saline). During the follicular phase of the menstrual cycle in healthy women, they observed no LH increases after IV bolus, subcutaneous bolus or 90-minute IV infusion of the hormone at maximal doses of 10 nmol/kg, 32 nmol/kg and 720 pmol/kg per minute, respectively. LH was, however, stimulated robustly after 10 nmol/kg IV bolus kisspeptin-10 (mean AUC increase: 30.3 IU/L; P<.05 vs. saline).
“Our results show that an injection of kisspeptin-10 in healthy men increased levels of sex hormones in the bloodstream in the hours following injection,” Jayasena said. “The women who responded with a similar increase in sex hormones were the ones who were ovulating at the time. We were very surprised at that outcome.”
Given the findings, the role of kisspeptin-10 may be explored with the aim to devise a way to induce ovulation, Jayasena said. “The absence of ovulation is a common problem which affects many women with infertility.”
Jayasena plans to conduct another study with a larger sample size that includes women of child-bearing age who do not ovulate. – by Louise Gagnon
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Disclosure: Dr. Jayasena reports no relevant financial disclosures.