The aging male hypothalamic-pituitary-gonadal axis: pulsatility and feedback.
Aging results in insidious decremental changes in hypothalamic, pituitary and gonadal function. The foregoing three main anatomic loci of control are regulated by intermittent time-delayed signal exchange, principally via gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and testosterone/estradiol (Te/E(2)). A mathematical framework is required to embody these dynamics. The present review highlights integrative adaptations in the aging male hypothalamic-pituitary-gonadal axis, as assessed by recent objective ensemble models of the axis as a whole.
Veldhuis
Johannes D
JD
Endocrine Research Unit, Department of Internal Medicine, Mayo Clinic College of Medicine, Mayo Clinic, 200 First Steet SW, Rochester, MN 55905, United States. veldhuis.johannes@mayo.edu
Keenan
Daniel M
DM
Liu
Peter Y
PY
Iranmanesh
Ali
A
Takahashi
Paul Y
PY
Nehra
Ajay X
AX
D000375:Aging / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D025461:Feedback, Physiological / Q000502:physiology*; D006066:Gonads / Q000502:physiology*; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism / Q000502:physiology*; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism; D008297:Male; D008954:Models, Biological; D011673:Pulsatile Flow / Q000502:physiology*; D013739:Testosterone / Q000097:blood / Q000378:metabolism
D013739:Testosterone; D007986:Luteinizing Hormone