Radiodetoxified lipopolysaccharide fails to activate the hypophyseal- pituitary-adrenal axis in the rat.
Lipopolysaccharide (LPS) is known to raise the concentration of the circulating stress hormones such as ACTH, corticosterone and beta-endorphin. This effect of endotoxin is mediated by different immune system-released hormone-like factors (e.g. interleukins, tumor necrosis factor etc.). Gamma-ray irradiation of LPS alters its biological properties and results in a radiodetoxified LPS preparation with numerous beneficial effects and decreased toxicity. In this study we compared the neuroendocrine effects of a commercial LPS and our native and radiodetoxified LPS preparations in rats. Plasma ACTH, corticosterone and beta-endorphin levels were measured by specific radioimmunoassays 120 min after intraperitoneal LPS administration. Control animals were injected with saline. Results show a dramatic increase in all hormones after administration of commercial and our native LPS preparation. Hormone levels in saline-injected controls and radiodetoxified LPS-treated rats did not rise significantly. These results suggest that radio-detoxification disintegrated that part of the LPS molecule complex which is responsible for toxicity including an enhanced production of cytokines, which trigger the hypothalamo-pituitary-adrenal axis.
Barna
I
I
Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary. barna@koki.hu
Bertók
L
L
Koenig
J I
JI
Makara
G B
GB
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D003345:Corticosterone / Q000097:blood; D005720:Gamma Rays; D007030:Hypothalamo-Hypophyseal System / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology* / Q000528:radiation effects*; D008297:Male; D010913:Pituitary-Adrenal System / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D001615:beta-Endorphin / Q000097:blood
D008070:Lipopolysaccharides; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone