Interactions of CRH, AVP and cortisol in the secretion of ACTH from perifused equine anterior pituitary cells: “permissive” roles for cortisol and CRH.
Abstract: To further elucidate the interaction of CRH, AVP and cortisol in the control of ACTH secretion, we used an in vitro perifusion model with dispersed equine anterior pituitary cells. To approximate the in vivo milieu in the horse, CRH was perifused continuously (at 0, 2 and 20 pmol/L) and 5-min pulses of AVP (0, 1, 3 and 10 nmol/L) were given every 30 min in the presence of 0 or 100 nmol/L cortisol. Total (baseline + incremental) ACTH secretion increased as both the CRH (p<0.001) and the AVP (p<0.001) concentration increased and interaction between CRH and AVP was significant (p=0.042). Cortisol reduced total ACTH secretion in the presence of 2 pmol CRH/L (p=0.001) but not 0 or 20 pmol CRH/L. For incremental ACTH there was interaction between CRH and AVP (p<0.0001), with increased secretion at higher concentrations, and no significant main effect of cortisol. There was significant (p=0.001) interaction between cortisol and CRH, with cortisol attenuating ACTH release at 0 pmol CRH/L (p=0.008), having no effect at 2 pmol CRH/L and potentiating it at 20 pmol CRH/L (p=0.026). We conclude that (1) CRH at high physiological levels has a "permissive" role in preventing the cortisol inhibition of the ACTH response to AVP, and (2) basal cortisol levels have a "permissive" action in priming the HPA axis for maximal responsiveness to stimulated levels of CRH and AVP.
Publication Date: 2000-10-06 PubMed ID: 11019907DOI: 10.3109/07435800009066179Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research aims to understand the interactions of CRH, AVP, and cortisol hormones in the secretion of ACTH from horse anterior pituitary cells. The findings reveal that high levels of CRH and cortisol have a “permissive” role in controlling ACTH release.
Experimental Process
- The researchers used an in-vitro model involving perifusion of dispersed equine anterior pituitary cells to shed light on how Corticotropin-releasing hormone (CRH), Arginine Vasopressin (AVP) and cortisol interact in controlling Adrenocorticotropic hormone (ACTH) secretion.
- CRH was continuously perifused at different concentrations (0, 2, and 20 pmol/L) to mirror the in vivo milieu in the horse. Additionally, 5-minute pulses of AVP (0, 1, 3, and 10 nmol/L) were given every 30 minutes, with both hormone concentrations given in the presence or absence of cortisol (0 or 100 nmol/L).
Results on ACTH Secretion
- ACTH secretion rise was observed with both an increase in CRH and AVP concentrations, indicating a significant correlation between these hormones and ACTH secretion.
- The interaction effect between CRH and AVP was significant, suggesting that these hormones don’t independently affect ACTH secretion but work together in some manner.
- Cortisol limited total ACTH secretion only in the presence of a specific CRH concentration, signifying a complex interaction between these hormones. At very high or low CRH concentrations, cortisol had no limiting effect.
- The findings also propose an important interplay between CRH and cortisol. The research noted that cortisol reduced ACTH release at low levels of CRH but increased it at high CRH levels.
Final Conclusion
- The “permissive” role of both CRH and cortisol is apparent from the research. At high physiological levels, CRH aids in preventing cortisol’s inhibitory effect on the ACTH response to AVP.
- Also, baseline cortisol levels appear to prime the HPA axis for maximal responsiveness to stimulated levels of CRH and AVP, thus emphasizing its “permissive” role.
- Ultimately, the study gives critical insights into the intricate network of hormonal controls of ACTH secretion.
Cite This Article
APA
Livesey JH, Evans MJ, Mulligan R, Donald RA.
(2000).
Interactions of CRH, AVP and cortisol in the secretion of ACTH from perifused equine anterior pituitary cells: “permissive” roles for cortisol and CRH.
Endocr Res, 26(3), 445-463.
https://doi.org/10.3109/07435800009066179 Publication
Researcher Affiliations
- Department of Endocrinology, Christchurch Hospital, New Zealand. johnl@chhlth.govt.nz
MeSH Terms
- Adrenocorticotropic Hormone / metabolism
- Animals
- Arginine Vasopressin / administration & dosage
- Arginine Vasopressin / pharmacology
- Corticotropin-Releasing Hormone / administration & dosage
- Corticotropin-Releasing Hormone / pharmacology
- Dose-Response Relationship, Drug
- Drug Interactions
- Female
- Horses / physiology
- Hydrocortisone / administration & dosage
- Hydrocortisone / pharmacology
- Kinetics
- Male
- Pituitary Gland, Anterior / metabolism
- Regression Analysis
Citations
This article has been cited 2 times.- Gelman PL, Flores-Ramos M, López-Martínez M, Fuentes CC, Grajeda JP. Hypothalamic-pituitary-adrenal axis function during perinatal depression. Neurosci Bull 2015 Jun;31(3):338-50.
- Andrews MH, Wood SA, Windle RJ, Lightman SL, Ingram CD. Acute glucocorticoid administration rapidly suppresses basal and stress-induced hypothalamo-pituitary-adrenal axis activity. Endocrinology 2012 Jan;153(1):200-11.
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