Spleen damage in endotoxaemic mice: the involvement of nitric oxide

• Autorzy: Yilmaz G. , Gursoy-Ozdemir Y. , Dogan A.I. , Gurdal H. , Gedikoglu G. , Dalkara T. , Guc M.O.
• Języki publikacji: EN

Abstrakty

EN

The association between Escherichia coli endotoxin-induced organ damage and nitric oxide-related mechanisms was investigated in the spleen of male Swiss albino mice (20—40 g) by using (1) Pt/Ir electrochemical sensor connected to an amperometric detection system (NO-501, InterMedical Co., Japan), (2) nitrotyrosine immunohistochemistry, (3) conventional light microscopy and (4) immunoblotting techniques in parallel. 1 h before endotoxin injection, animals were pretreated with either nitric oxide synthase inhibitor, L-N G -nitroarginine methyl ester (L-NAME, 20 mg kg -1 , i.p.) or inducible nitric oxide synthase expression inhibitor, dexamethasone (5 mg kg -1 , i.p.) or the inhibitor of murine inducible nitric oxide synthase in vivo, 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT, 1 mg kg -1 , i.p.). 5 h after endotoxin treatment, electrochemically detected concentration of nitric oxide was significantly elevated (nM, endotoxin: 716.6 ± 178.2, n = 10 vs saline: 209.4 ± 127.8, n = 9, P = 0.0312, unpaired Student’s t-test) and remained so throughout the 30 min monitorization period. Neither dexamethasone nor AMT blocked the endotoxin-induced overproduction of nitric oxide indicating that the enhanced inducible nitric oxide synthase activity cannot be the only explanation. When dexamethasone and L-NAME combination was used to block both the constitutive and the inducible isoforms, nitric oxide production was virtually abolished, indicating a significant contribution from the constituve isoform of nitric oxide synthase. The results of nitrotyrosine immunohistochemistry and the conventional light microscopy were also in agreement with the amperometric method while immunoblotting revealed the expression of both the endothelial and the inducible isoforms of nitric oxide synthase were induced in endotoxaemic animals. Thus, we conclude that endotoxin-induced splenic damage in endotoxaemia can be explained by enhanced production of nitric oxide due to the induction of both endothelial and inducible nitric oxide synthases while causal relationship and the roles of other deleterious mediators such as oxygen-derived free radicals are yet to be established.

Słowa kluczowe

EN

mouse; mice; spleen; nitric oxide; nitrotyrosine immunohistochemistry; immunoblotting technique; amperometry; electrochemical sensor; septic shock; Escherichia coli

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2001
• Tom: 52
• Numer: 4,2
• Opis fizyczny: p.729-744,fig.

Twórcy

autor

Yilmaz G.

• Hacettepe University, Ankara, Turkey

autor

Gursoy-Ozdemir Y.

autor

Dogan A.I.

autor

Gurdal H.

autor

Gedikoglu G.

autor

Dalkara T.

autor

Guc M.O.