Regulation of Pulsatile and Entropic ACTH Secretion Under Fixed Exogenous Secretagogue Clamps

Roelfsema, Ferdinand; Aoun, Paul; Takahashi, Paul Y.; Erickson, Dana; Yang, Rebecca; Veldhuis, Johannes D.

doi:10.1210/jc.2017-00115

Cited by 5 publications

(10 citation statements)

References 31 publications

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“…The potential of the extended model under selected conditions to anticipate a synergistic effect in the HPA axis ultradian dynamics response was verified in in silico experiments with perturbations induced by repeating single-pulse changes in CRH and AVP concentrations applied both separately and simultaneously (Figure 5). The observed qualitative similarity between response patterns of the HPA axis to perturbation with CRH solely and conjointly with AVP (Figures 5B, D) can be also found between the results of experiments in humans with 10hour infusions of CRH and of both peptides simultaneously (39). Although cortisol oscillations obtained by the proposed model are extremely regular (both in period and amplitude) (Figure 5A), the ones obtained after series of single-pulse perturbations that were regular in intensity and time of application, are irregular (chaotic) (Figures 5B-D).…”

Section: Discussionsupporting

confidence: 66%

“…Whenever possible, values of rate constant of reaction steps related to the initial model (not in bold in Table 1 ) were the same as in our previous papers ( 57 , 58 ). Values of the rate constants of reaction steps (R2.2), (R4), (R5.2), (R5.3) and (R12), associated with AVP effects were derived from ( 39 , 54 , 59 , 60 ) unless otherwise specified.…”

Section: Methodsmentioning

confidence: 99%

“…However, AVP has received the most attention among them so far, due to its relevant role and effects on corticotrope cells' function and HPA axis activity. Namely, it has been indicated that both CRH and AVP act on their own receptors (28-32) on corticotrope cells in anterior pituitary to stimulate adrenocorticotropic hormone (ACTH) production and release with different (26,(33)(34)(35)(36)(37)(38)(39)(40)(41) or even similar potencies (42). Moreover, CRH and AVP are also capable of potentiating each other's activity (37,38).…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, CRH and AVP are also capable of potentiating each other's activity (37,38). Their synergistic stimulation of ACTH production and secretion by corticotrope cells could yield a several-fold higher output than due to the action of either one individually (26,(34)(35)(36)(37)(38)(39)(40)(41)(43)(44)(45)(46)(47). However, the exact mechanism underlying their individual and synergistic action is yet to be clarified.…”

Section: Introductionmentioning

confidence: 99%

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Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis

Stojiljković

Čupić²,

Maćešić³

et al. 2022

Front. Endocrinol.

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Numerous studies on humans and animals have indicated that the corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) stimulate both individually and synergistically secretion of adrenocorticotropic hormone (ACTH) by corticotropic cells in anterior pituitary. With aim to characterize and better comprehend the mechanisms underlying the effects of AVP on Hypothalamic-Pituitary-Adrenal (HPA) axis ultradian dynamics, AVP is here incorporated into our previously proposed stoichiometric model of HPA axis in humans. This extended nonlinear network reaction model took into account AVP by: reaction steps associated with two separate inflows of AVP into pituitary portal system, that is synthesized and released from hypothalamic parvocellular and magnocellular neuronal populations, as well as summarized reaction steps related to its individual and synergistic action with CRH on corticotropic cells. To explore the properties of extended model and its capacity to emulate the effects of AVP, nonlinear dynamical systems theory and bifurcation analyses based on numerical simulations were utilized to determine the dependence of ultradian oscillations on rate constants of the inflows of CRH and AVP from parvocellular neuronal populations, the conditions under which dynamical transitions occur due to their synergistic action and, moreover, the types of these transitions. The results show that under certain conditions, HPA system could enter into oscillatory dynamic states from stable steady state and vice versa under the influence of synergy reaction rate constant. Transitions between these dynamical states were always through supercritical Andronov-Hopf bifurcation point. Also, results revealed the conditions under which amplitudes of ultradian oscillations could increase several-fold due to CRH and AVP synergistic stimulation of ACTH secretion in accordance with results reported in the literature. Moreover, results showed experimentally observed superiority of CRH as a stimulator of ACTH secretion compared to AVP in humans. The proposed model can be very useful in studies related to the role of AVP and its synergistic action with CRH in life-threatening circumstances such as acute homeostasis dynamic crisis, autoimmune inflammations or severe hypovolemia requiring instant or several-days sustained corticosteroid excess levels. Moreover, the model can be helpful for investigations of indirect AVP-induced HPA activity by exogenously administered AVP used in therapeutic treatment.

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Section: Discussionsupporting

confidence: 66%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis

Stojiljković

Čupić²,

Maćešić³

et al. 2022

Front. Endocrinol.

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“…Although the mechanisms underlying these variations of HPA axis rhythms among species have not been extensively analyzed, specific features of HPA axis regulation in sheep are worth mentioning. The parvocellular neurons of the hypothalamic paraventricular nucleus release the neurohormones CRH and AVP, regulating ACTH secretion in a pulsatile manner (Roelfsema et al 2017). This may be linked to the daily regulation mode of ACTH secretion controlled by CRH and AVP.…”

Section: Cortisolmentioning

confidence: 99%

Comparative diurnal and seasonal variations of ACTH, cortisol and aldosterone in Ouled Djellal and D’Man sheep breeds reared in arid lands

et al. 2022

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Abstract. Amokrane-Ferrah A, Annane A, Ferrouk-Boukenaoui N, Khaldoun M, Amirat Z, Mormede P, Khammar F. 2021. Comparative diurnal and seasonal variations of ACTH, cortisol and aldosterone in Ouled Djellal and D’Man sheep breeds reared in arid lands. Biodiversitas 23: 388-395. This study aimed to explore the diurnal and seasonal variations of adrenocorticotropic hormone (ACTH), cortisol and aldosterone, main hormones involved in adaptation to the harsh climate of the Sahara Desert in two breeds of sheep (Ovis aries Linnaeus, 1758), Ouled Djellal rams (seasonal breeder) and D'Man (no seasonal breeder). Blood samples were taken every hour for 24 hours during equinoxes and solstices. Plasma ACTH levels were similar in the two breeds, with higher levels in the morning and a seasonal rhythm characterized by lower levels and dampened diurnal cycle in winter. In most experimental conditions, plasma cortisol levels showed no circadian rhythm but marked ultradian variations. The seasonal cortisol rhythm was different from the ACTH rhythm and characterized by lowest levels at equinoxes and highest levels in summer. Mean cortisol levels were higher in Ouled Djellal than in the D’Man breed, which may favor better robustness of Ouled Djellal sheep. Plasma aldosterone levels were characterized by diurnal variations with an acrophase around midnight, with large differences across breeds and seasons. In contrast to cortisol, the seasonal rhythm of plasma aldosterone showed the highest levels at equinoxes and lowest at solstices. These changes can be driven by environmental conditions and exceptionally high summer temperatures.

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Hypothalamic Regulation of Anterior Pituitary Function

Ben-Shlomo¹,

Melmed²

2022

The Pituitary

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Regulation of Pulsatile and Entropic ACTH Secretion Under Fixed Exogenous Secretagogue Clamps

Cited by 5 publications

References 31 publications

Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis

Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis

Comparative diurnal and seasonal variations of ACTH, cortisol and aldosterone in Ouled Djellal and D’Man sheep breeds reared in arid lands

Hypothalamic Regulation of Anterior Pituitary Function

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