Female sex steroids: effects upon microglial cell activation

Estrogen-mediated impairment of macrophageal uptake of environmental TiO2particles to explain inflammatory effect of TiO2on airways during pregnancy

“…Even though estradiol levels used in vitro here may be higher than those that reach AM in vivo, such exaggeration of stimulant is not uncommon in experimental models and should not detract from the mechanistic data reported here. For instance, Drew & Chavis (2000) reported inhibitory effects of estradiol and progesterone on microglial macrophages at concentrations of up to 100 mM, a level 3-times the highest levels used in the current study. Of note also is the potentiating effect of progesterone, which was not effective alone; thus, in vivo in tissues, relatively lower doses may cause the effect due to such interactions with other factors.…”

Estrogen anti-inflammatory activity in brain: A therapeutic opportunity for menopause and neurodegenerative diseases

“…This effect was antagonized by ICI182,780, an estrogen receptor antagonist, suggesting a receptor-mediated effect of the hormone and ERa appeared to be selectively involved in estradiol anti-inflammatory activity in brain macrophages ( [82,242]). Other authors further confirmed these observations using primary cultures of microglia as well as cell lines and assaying estrogen-dependent attenuation of microglia activation in terms of reduced phagocytic activity, production of reactive oxygen and nitrogen species and other factors of the inflammatory cascade ( [26,43,61,141,262]). Meanwhile, a better evaluation of neurological and neurodegenerative diseases has also pointed to a potential role of estrogens in the pathogenesis and progression of several neuroinflammatory and neurodegenerative diseases, thus providing a new strength to the hypothesis of the potential benefits of the use of estrogenic compounds in the treatment of these disorders.…”

The organizational and activational effects of sex hormones on tactile and thermal hypersensitivity following lumbar nerve root injury in male and female rats

“…There is evidence for gonadal hormone stimulation of neurogenesis (Breedlove et al, 1983;Nordeen et al, 1985) and apoptosis (Nilsen et al, 2000), synapse formation (McEwen et al, 2001) and synapse elimination (Calizo and Flanagan-Cato, 2002), neuropeptide expression (De Vries, 1990), and glial modulation (Drew and Chavis, 2000;McCarthy et al,2002). The seemingly ubiquitous and contradictory nature of all of these actions has confounded the development of a singular mechanistic hypothesis that accounts for the effects of gonadal hormones in the modulation of nociceptive sensitivity.…”