Hypothalamic-pituitary-adrenal axis, role

Heim C, Ehlert U, Rexhausen J, Hanker JP, Hellhammer DH (1998) Abuse-related post-traumatic stress disorder and alterations of the hypothalamic-pituitary-adrenal axis in women with chronic pelvic pain. Psychosom Med 60 309-318 Heim C, Ehlert U, Hellhammer DH (2000) The potential role of hypocortisolism in the pathophysiology of stress-related bodily disorders. Psychoneuroendocrinology 25 1 -35 Heim C, Newport DJ, BonsaU R, MiUer AH, Nemeroff CB (2001) Altered pituitary-adrenal axis responses to provocative challenge tests in adult survivors of childhood abuse. Am J Psychiatry 158 575-581... 

Webster JI, Sternberg EM. Role of the hypothalamic-pituitary-adrenal axis, glucocorticoids and glucocorticoid receptors in toxic sequelae of exposure to bacterial and viral products. 7 Endocrinol. 2004 181 207-221. 

Cassano WJ, Jr, D mello AP. Acute stress-induced facilitation of the hypothalamic-pituitary-adrenal axis Evidence for the roles of stressor duration and serotonin. Neuroendocrinology 2001 74 167-177. 

The past 20 years have witnessed a broad interest in the role of the hypothalamic-pituitary-adrenal axis in the psychobiology of affective disorders. In depressed patients, increases in serum cortisol are frequently reported in addition to disruptions of circadian patterns of cortisol secretion... 

Experimental evidence suggests that sigma receptors play an important role in regulating and integrating both immune and endocrine functions. In experimental studies, it has been shown that the selective sigma ligand N-allyl-normetazocine stimulates the hypothalamic-pituitary-adrenal axis... 

Corticotrophin releasing hormone (CRH), a peptide synthesised in the paraventricular nucleus, suppresses appetite and food intake in addition to its role in the regulation of the hypothalamic-pituitary-adrenal axis. 

IL-6 acts on the pituitary to induce adrenocorticotropic hormone (ACTH) release and directly on the adrenal glands to produce glucocorticoids. It is known that different cytoldnes that share gpl30 as a receptor subunit induce serum amyloid A, and potentiate the induction of IL-6 and the activation of the hypothalamic-pituitary-adrenal axis by IL-1. In particular, LIF, OSM, IL-11, and cardiotrophin-1 potentiate the elevation of serum corticosterone and IL-6 levels induced by IL-1. Furthermore, the potentiation of IL-1-induced serum corticosterone levels is not a consequence of the increased serum IL-6 observed after IL-1 administration. Thus either endogenous IL-6 does not mediate IL-l-induced corticosterone increase, or its role may be fulfilled by other cytokines. This is very important in the understanding of the activation of the hypothalamic-pituitary-adrenal axis and that potentiation of acute phase protein synthesis may represent an important feedback regulatory mechanism of inflammation. ... 

Different evidence suggests that the endocannabinoid system plays an important role in the regulation of emotional-like behaviour. Thus, the CBi cannabinoid receptor is widely distributed in limbic and cortical areas involved in the control of emotion. The administration of cannabinoid ligands produces emotional-like responses in different behavioural paradigms. Furthermore, cannabinoids also exert a modulatory role on the activity of the hypothalamic-pituitary adrenal axis (HPA), and these compounds modulate the release of several neurotransmitters involved in emotional behaviour, including CCK and GABA,... 

C. Role of Hypothalamic-Pituitary-Adrenal Axis in Regulating Immunity... 

Jackson, A.L. and Murphy, L.L. (1997) Role of the hypothalamic-pituitary-adrenal axis in the suppression of luteinizing hormone release by delta-9-tetrahydrocannabinol. Neuroendocrinology 65 446 52. 

In addition to the role of higher centers, a hypothalamic-pituitary-adrenal axis-mediated mechanism for scrapie-induced obesity has been suggested (Kim et al., 1988). Adrenals in the scrapie-induced mice were significantly larger than controls and adrenalectomy performed before ME7 injection... 

Several lines of evidence support the neurotrophic hypothesis. Animal and human studies indicate that stress and pain are associated with a drop in BDNF levels and that this loss of neurotrophic support contributes to atrophic structural changes in the hippocampus and perhaps other areas such as the medial frontal cortex and anterior cingulate. The hippocampus is known to be important both in contextual memory and regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Likewise, the anterior cingulate plays a role in the integration of emotional stimuli and attention functions, whereas the medial orbital frontal cortex is also thought to play a role in memory, learning, and emotion. 

Deficits in several neurotransmitters, in addition to somatostatin and CRF, have consistently been reported to occur in AD. In addition, the density of CRF receptors appears to be increased while those for somatostatin are either decreased or unchanged. The changes in both the brain and the CSF concentration of CRF would, unlike those in somatostatin, appear to occur relatively early in the disease and correlate with the severity of the condition. Such changes may be reflected in a dysfunctional hypothalamic-pituitary-adrenal (HPA) axis that may play an important role in the pathology of AD. 

While the existence of corticotropin-releasing factor (CRF) was first proposed in 1955 it took 26 years to develop the isolation (RP-HPLC) and sequencing tools (microsequencing) that led to its characterization in 1981.P l First isolated from ovine hypothalanni,P l CRF was subsequently characterized from rat hypothalami P l the identical structure was deduced for human CRF (hCRF) on the basis of the cDNA sequence of the hCRF precursor gene.P CRF plays a major role in the maintenance or restoration of homeostasis by regulating the activity of the hypothalamic-pituitary-adrenal (HPA) axis.b°l Its first synthesis stretched the limits of SPPS capabilities and of preparative HPLC.P l... 

FI) male mice and divided them into two groups. One group was injected i.p. with zymosan to induce peritoneal inflammation and the other simultaneously with antalarmin, a CRH-1 receptor antagonist, to block hypothalamic-pituitary-adrenal (HPA) axis function. After 24 h of injection the mice were killed by CO2 asphyxia, and the peritoneal leukocytes (PTLs) isolated and counted. Additionally, the levels of ROS and COX activity were detected in PTLs by fluorometric and colorimetric assays, respectively. The result was that TTO inhalation led to a strong anti-inflammatory effect on the immune system stimulated by zymosan injection, whereas PTL number, ROS level, and COX activity in mice without inflammation were not affected. The HPA axis was shown to play an important role in the anti-inflammatory effect of TTO and antalarmin was observed to abolish the influence of inhaled TTO on PTL number and their ROS expression in mice with experimental peritonitis. In mice without inflammation these parameters were not affected. 

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