madman
Super Moderator
Abstract
The present study was designed to assess the responsiveness of the hypothalamic-pituitary-gonadal axis to kisspeptin administration with increasing age in men. Human kisspeptin‐10 was administered in a single iv bolus dose (1 µg/kg BW) to healthy adult, middle and advanced-age men. Serial blood samples were collected for 30 min pre‐ and 120 min post‐kisspeptin injection periods at 30‐min interval. Analysis of plasma LH by ELISA showed a significant (p < 0.05) increase after kisspeptin‐10 administration in all groups, whereas plasma testosterone concentration, was significantly elevated (p < 0.05) after kisspeptin‐10 injection only in the adult men group. Present results suggest that in men, the central hypothalamic-pituitary axis remains active and shows responsiveness to kisspeptin stimulation across life. However, Leydig cell responsiveness to kisspeptin‐induced LH decreases with age in men.
5 CONCLUSION
Conclusively, the present study suggests that KP‐10 raises plasma LH secretion in adult, middle and advanced-age men equally. Plasma testosterone concentration of adult-age men is increased by iv bolus administration of KP‐10 while no increase occurs in circulating testosterone concentration of middle‐aged and advanced-age men. Our findings suggest that in men central hypothalamic-pituitary axis remains active and shows responsiveness to KP‐10 across the life, but Leydig cell responsiveness to gonadotropin decreases with age. These results will provide a great insight into the understanding of kisspeptin physiology in the reproductive system.
The present study was designed to assess the responsiveness of the hypothalamic-pituitary-gonadal axis to kisspeptin administration with increasing age in men. Human kisspeptin‐10 was administered in a single iv bolus dose (1 µg/kg BW) to healthy adult, middle and advanced-age men. Serial blood samples were collected for 30 min pre‐ and 120 min post‐kisspeptin injection periods at 30‐min interval. Analysis of plasma LH by ELISA showed a significant (p < 0.05) increase after kisspeptin‐10 administration in all groups, whereas plasma testosterone concentration, was significantly elevated (p < 0.05) after kisspeptin‐10 injection only in the adult men group. Present results suggest that in men, the central hypothalamic-pituitary axis remains active and shows responsiveness to kisspeptin stimulation across life. However, Leydig cell responsiveness to kisspeptin‐induced LH decreases with age in men.
5 CONCLUSION
Conclusively, the present study suggests that KP‐10 raises plasma LH secretion in adult, middle and advanced-age men equally. Plasma testosterone concentration of adult-age men is increased by iv bolus administration of KP‐10 while no increase occurs in circulating testosterone concentration of middle‐aged and advanced-age men. Our findings suggest that in men central hypothalamic-pituitary axis remains active and shows responsiveness to KP‐10 across the life, but Leydig cell responsiveness to gonadotropin decreases with age. These results will provide a great insight into the understanding of kisspeptin physiology in the reproductive system.
