Hormonal control of inflammatory responses

Abstract

Almost any stage of inflammatory and immunological responses is affected by hormone actions. This provides the basis for the suggestion that hormones act as modulators of the host reaction against trauma and infection. Specific hormone receptors are detected in the reactive structures in inflamed areas and binding of hormone molecules to such receptors results in the generation of signals that influence cell functions relevant for the development of inflammatory responses. Diversity of hormonal functions accounts for recognized pro- and anti-inflammatory effects exerted by these substances. Most hormone systems are capable of influencing inflammatory events. Insulin and glucocorticoids, however, exert direct regulatory effects at concentrations usually found in plasma. Insulin is endowed with facilitatory actions on vascular reactivity to inflammatory mediators and inflammatory cell functions. Increased concentrations of circulating glucocorticoids at the early stages of inflammation results in downregulation of inflammatory responses. Oestrogens markedly reduce the response to injury in a variety of experimental models. Glucagon and thyroid hormones exert indirect anti-inflammatory effects mediated by the activity of the adrenal cortex. Accordingly, inflammation is not only merely a local response, but a hormone-controlled process.

Down-regulation of mast cell activation and airway reactivity in diabetic rats: role of insulin

“…Experimental findings agree with clinical evidence that striking examples of this issue are premenstrual exacerbation of asthma [1,2], worsening of asthma and chronic urticaria by hyperthyroidism [3,4], and the reciprocal exclusion between atopic diseases and diabetes mellitus [5,6]. Experimental evidence indicates that an overall reduced inflammatory reaction is observed whenever a relative lack of insulin occurs in an organism [7]. Altered vascular responsiveness to inflammatory mediators [8,9], defective leukocyte-endothelial interactions and inflammatory cell dysfunctions [10,11] are described in insulin-deficient states.…”

Antigen-induced pleural eosinophilia is suppressed in diabetic rats: role of corticosteroid hormones

“…We have reported that insulin treatment was able to reverse the suppression of allergic eosinophilia in diabetic rats (Diaz et al 1996). Thus, considering that glucocorticoids and insulin have opposing biological effects in several systems (Garcia-Leme & Farsky 1993), it is valid to speculate that the balance between systemic levels of these hormones may be important to determine the intensity of allergic eosinophilic response.…”

Effects of Administration of Alpha-Melanocyte Stimulating Hormone (α-MSH) on Some Hematological Values of Alloxan-induced Diabetic Rats

“…It has been suggested that the heart rate is higher, red and white blood cells counts lower in type diabetes than in non-diabetic [10,11] . There is some evidence that diabetics present a deficiency in mounting an inflammatory response, probably associated with severe reduction in insulin secretion rather than increased blood glucose levels [1,2,13] . This is still a controversial point as other investigators have suggested a direct correlation between hyperglycemia and the incidence of infection in diabetic patients [14] .…”