Secretion of anterior and posterior pituitary hormones, adrenal glucocorticoids, mineralocorticoids and catecholamines, gonadal sex steroids, parathormone, insulin and glucagon is pulsatile (burst-like or episodic). Neuronal inputs, cellular excitability and feedback with time delays constitute proximate mechanisms driving recurrent pulses. Both the amplitude and frequency of gonadotropin, thyrotropin, prolactin and sex-steroid pulses determine their mean concentrations. In contradistinction, primarily the amplitude of growth hormone, adrenocorticotropin, cortisol, parathormone and insulin pulses controls their average values. Gonadotropin-releasing hormone and growth-hormone pulses convey unique signaling information to target tissues. Evaluation of the mechanisms that govern pulsatile hormone secretion requires simultaneous quantification of the number, size and shape of secretory bursts, underlying nonpulsatile (basal) secretion and associated elimination kinetics. The necessary methodology is termed deconvolution analysis. More complex ensemble models are used to interlink neurohormone signals by estimating endogenous dose-response curves noninvasively. The approximate entropy statistic is a specific and sensitive measure of feedback fidelity within an ensemble system, Implications of neurohormone pulsatility include regulation of somatic growth, reproduction, muscle and bone mass, visceral fat burden, glucose metabolism, parturition, and sodium and water balance.
|Original language||English (US)|
|Title of host publication||Ultradian Rhythms from Molecules to Mind|
|Subtitle of host publication||A New Vision of Life|
|Number of pages||20|
|State||Published - Dec 1 2008|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)