Karolina Skorupskaite1, Jyothis T George2,3, Johannes D Veldhuis4, Robert P Millar5,6, Richard A Anderson1. 1. MRC Centre for Reproductive Health, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK. 2. Warwick Medical School, Coventry, UK. 3. Boehringer Ingelheim, Bracknell, UK. 4. Endocrine Research Unit, Center for Translational Science Activities, Mayo Clinic, Rochester, MN, USA. 5. Centre for Neuroendocrinology and Mammal Research Institute, University of Pretoria, Pretoria, South Africa. 6. Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
Abstract
OBJECTIVE: Patients with mutations of neurokinin B (NKB) and its receptor show hypogonadotrophic hypogonadism, but there is little evidence for the importance of this pathway in reproductive function in normal men, or its functional hierarchy with kisspeptin. DESIGN: An open label study wherein men (n = 6) were administered the NK3R antagonist MLE4901 40 mg orally twice a day for 7 days. Kisspeptin-10 (0.3 μg/kg iv bolus) was given before and on day 7 of NK3R antagonist treatment. PATIENTS: Subjects were healthy men. MEASUREMENTS: Reproductive hormones were measured before and during the NK3R antagonist administration, including frequent sampling on two occasions for analysis of pulsatile LH secretion. RESULTS: LH, FSH and testosterone secretion were decreased during NK3R antagonist administration. LH showed a biphasic response, being reduced after 24 hours of treatment (4.5 ± 0.6 IU/L pretreatment to 1.7 ± 0.2 IU/L, P < .05), with partial recovery thereafter, but it was again decreased on day 7 (2.5 ± 0.6 IU/L, P < .05 vs pretreatment). FSH secretion was also suppressed, with a similar temporal pattern to that of LH. Testosterone secretion was decreased from 24 hours (18.4 ± 1.6 pretreatment vs 5.6 ± 1.5 nmol/L, P < .01) and remained suppressed throughout the treatment period. Analysis of LH pulsatility showed that both basal and pulsatile LH secretion were markedly suppressed but there was no detected change in LH pulse frequency. Kisspeptin-10 stimulated LH secretion, with similar responses before and during NK3R antagonist administration. CONCLUSIONS: These data demonstrate a central role for NKB/NK3R in the physiological regulation of reproductive function in men, and that this is functionally upstream of kisspeptin-mediated GnRH secretion.
OBJECTIVE:Patients with mutations of neurokinin B (NKB) and its receptor show hypogonadotrophic hypogonadism, but there is little evidence for the importance of this pathway in reproductive function in normal men, or its functional hierarchy with kisspeptin. DESIGN: An open label study wherein men (n = 6) were administered the NK3R antagonist MLE4901 40 mg orally twice a day for 7 days. Kisspeptin-10 (0.3 μg/kg iv bolus) was given before and on day 7 of NK3R antagonist treatment. PATIENTS: Subjects were healthy men. MEASUREMENTS: Reproductive hormones were measured before and during the NK3R antagonist administration, including frequent sampling on two occasions for analysis of pulsatile LH secretion. RESULTS:LH, FSH and testosterone secretion were decreased during NK3R antagonist administration. LH showed a biphasic response, being reduced after 24 hours of treatment (4.5 ± 0.6 IU/L pretreatment to 1.7 ± 0.2 IU/L, P < .05), with partial recovery thereafter, but it was again decreased on day 7 (2.5 ± 0.6 IU/L, P < .05 vs pretreatment). FSH secretion was also suppressed, with a similar temporal pattern to that of LH. Testosterone secretion was decreased from 24 hours (18.4 ± 1.6 pretreatment vs 5.6 ± 1.5 nmol/L, P < .01) and remained suppressed throughout the treatment period. Analysis of LH pulsatility showed that both basal and pulsatile LH secretion were markedly suppressed but there was no detected change in LH pulse frequency. Kisspeptin-10 stimulated LH secretion, with similar responses before and during NK3R antagonist administration. CONCLUSIONS: These data demonstrate a central role for NKB/NK3R in the physiological regulation of reproductive function in men, and that this is functionally upstream of kisspeptin-mediated GnRH secretion.
Authors: Richard A Anderson; Jennifer Cormier; Ruth Thieroff-Ekerdt; Malcolm Boyce; Frans van den Berg; Daniel Grau; David Turnquist; Deya Corzo; Philip Graham Journal: J Clin Endocrinol Metab Date: 2020-12-01 Impact factor: 5.958
Authors: Aleisha M Moore; Lique M Coolen; Danielle T Porter; Robert L Goodman; Michael N Lehman Journal: Endocrinology Date: 2018-09-01 Impact factor: 5.051
Authors: Karolina Skorupskaite; Jyothis T George; Johannes D Veldhuis; Robert P Millar; Richard A Anderson Journal: Hum Reprod Date: 2020-06-01 Impact factor: 6.918