Estradiol inhibits astrocytic GFAP expression in an animal model of neuroinflammation

There are many animal models for studying different aspects of neurodegener ation. Lipopolysaccharide (LPS) injected in rats intracerebroventricularly induces neuroinflammation quite similar to the inflammatory component of ch ronic neurodegenerative conditions such as Alzheimer's disease. We used thi s model to examine the effect of estradiol on neuroinflammation. LPS or pyr ogen-free saline were injected intracerebroventricularly (i.c.v.) into the lateral ventricle of male Wistar rats and estradiol was administered (200 m ug/kg s.c.) 48 h before or 24 h after LPS injection. LPS-induced body weigh t loss was partially postponed by the treatment, especially in the rats pre treated with estradiol. When analyzing GFAP glial cell morphology in the CA 3c area of the hippocampus and corpus callosum, as well as the number of as troglial asrroglial cells in CA3c and CA I, GFAP expression was found to be reduced This was true especially in the animals pretreated with estradiol and to a much lesser extent in the posttreated ones. The data support the p ossible existence of a neuroimmunomodulatory effect of estradiol administra tion in neurodegenerative conditions, which influences the inflammatory com ponent. (C) 2001 Prous Science. All rights reserved.