Pituitary-adrenal system

Ritchie, JC and Nemeroff, CB (1991) Stress, the hypothalamic-pituitary-adrenal axis and depression. In Stress, Neuropeptides and Systemic Disease (Eds McCubbin, JA, Kaufmann, PG and Nemeroff, CB), Academic Press, London, pp. 181-197. 

It is important to remember that adverse effects of topical corticosteroids may be systemic in nature and hypothalamic-pituitary-adrenal axis suppression can occur, especially when high-potency corticosteroids are used. Infants and small children may be more susceptible due to their increased skin sur-face body mass ratio.18 Topical corticosteroids may also cause striae, skin atrophy, acne, telangiectasias, and rosacea.2,10,18 Atrophy can result in thin, fragile, easily lacerated skin. Striae are caused by tearing of dermal connective tissue and are irreversible.18 Due to their significant adverse-effect profile, it has been recommended that no topical corticosteroid be used regularly for more than 4 weeks without review and reassessment.2... 

Imura, H and Fukata, J., Endocrine-paracrine interaction in communication between the immune and endocrine systems. Activation of the hypothalamic-pituitary-adrenal axis in inflammation. Eur. J. Endocrinol. 130,32-37 (1994). 

Hypothalamic-Pituitary-Adrenal (HPA) axis An integrated neuroendocrine system linking the hypothalamus (noradrenaline and corticotropin-releasing factor CRF) with the anterior pituitary (corticotropin or ACTH) and the adrenal cortex (cortisol). 

The sympathetic nervous system (SNS) and the hypothalamic-pituitary axis work together as important modulators of the immune system after exposure to stressors. Norepinephrine (NE) and epinephrine (EPI) (catecholamines from the SNS) and neuroendocrine hormones modulate a range of immune cell activities, including cell proliferation, cytokine and antibody production, lytic activity, and migration. This chapter will focus on these two major pathways of brain-immune signaling, briefly summarizing the evidence for SNS and hypothalamic-pituitary-adrenal (HPA) modulation of immune function, their influence on immune-mediated diseases, immune modulation in aging, and early life influences on these pathways. 

Karrow, N. A., Activation of the hypothalamic-pituitary-adrenal axis and autonomic nervous system during inflammation and altered programming of the neuroendocrine-immune axis... 

Psychological stress may influence the immune system by activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary axis (SAM). The well-described innervation of primary and secondary lymphoid tissues by the autonomic nervous system also has been implicated in stress-related modulation of the immune response. These pathways operate by producing biological mediators that interact with and affect cellular components of the immune system.13... 

Neuropsychological impairments in mood disorders, particularly those of working memory and executive function, are the most convincing and objective demonstrations of an impairment of consciousness. Since these impairments do not correlate with the severity of the mood disturbance and persist upon recovery they are not simply epiphenomena of the mood disturbance but rather may index trait pathology in susceptible individuals. It has previously been argued that mood disturbance and neuropsychological impairment may result from disturbances in two different neurochemical systems, the serotonin (5-HT) system and the hypothalamic-pituitary-adrenal (HPA) axis, between which there is a close interaction (McAllister-Williams et al., 1998). 

Increasing the concentration increases the penetration, but not to the same degree. Solubility of the corticosteroid in the vehicle is an other determinant of absorption and efficacy. So different formulations of the same corticosteroid can end up in a different efficacy classification. Efficacy can be further augmented by using the corticosteroid under occlusion. Occlusion with plastic enhances penetration and also absorption. However, with increased absorption also the risk of systemic side-effects increases. Systemic absorption will suppress the pituitary-adrenal axis and may cause Cushing s syndrome and a plethora of other adverse events (see Chapter 24, Section Il.b). Even small amounts absorbed may already cause growth retardation in children. 

Data of animal experiments discussed in this chapter suggest a variety of potential pharmacological targets for the treatment of pathological anxiety (Fig. 1). As the occurrence of traumatic events is usually unpredictable, it seems more promising to interfere with consolidation than with acquisition processes. In this context, the sympatho-adrenergic and the hypothalamic-pituitary-adrenal system are of particular interest. Both noradrenaline and corticosterone/cortisol are known to facilitate memory consolidation, in par-... 

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