Expression of neuronal and inducible nitric oxide synthases in the thymus under normal conditions and after administration of bacterial endotoxin.
The topography of thymocytes expressing neuronal and inducible nitric oxide synthases and changes in the content of luminescent immunoreactive products in these cells after intraperitoneal injection of bacterial lipopolysaccharide were studied by double immunohistochemical labeling. Under normal conditions neuronal nitric oxide synthase-immunopositive cells formed a wide network in thymus medulla (except for perivascular regions). Inducible nitric oxide synthase was expressed in single cells at the corticomedullary boundary. Lipopolysaccharide markedly increased the intensity of luminescence and number of inducible nitric oxide synthase-immunoreactive cells. However, this agent sharply decreased the intensity of luminescence in neuronal nitric oxide synthase-immunopositive cells of the stroma. Our results indicate that neuronal and inducible nitric oxide synthases are synthesized in various stromal cells of the thymus. Expression of these enzyme isoforms undergoes opposite changes during inflammation.
Titova
I V
IV
Institute of Experimental Endocrinology, Research Center for Endocrinology, Russian Academy of Medical Sciences, Russia.
Sergeev
V G
VG
Yarilin
A A
AA
Akmaev
I G
IG
D000818:Animals; D004731:Endotoxins / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic; D008163:Luminescent Measurements; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D051381:Rats; D017207:Rats, Sprague-Dawley; D013950:Thymus Gland / Q000033:anatomy & histology / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*
D004731:Endotoxins; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat