Overexpression of inducible nitric oxide synthase and cyclooxygenase-2 in rat zinc-deficient lung: Involvement of a NF-kappaB dependent pathway.
Reactive oxygen and nitrogen species have been implicated in the pathogenesis of pulmonary diseases. The goal of this study was to measure the response of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 enzymes (COX-2) in lung with moderate zinc deficiency. Adult male Wistar rats were divided into two groups receiving (1) a zinc-deficient diet (ZD) or (2) a zinc-adequate control diet. After 2 months of treatment, the zinc-deficient group showed a significant pulmonary edema. This was associated to a reduction of protein thiols and to a significant increase of metallothionein and glutathione disulfide levels. In addition, a higher serum and lung NO production in ZD group was positively related to the higher activity and expression of iNOS and COX-2 found in lungs. Western blot analysis revealed increased IkappaBalpha degradation, an indicator of NF-kappaB activation in ZD lungs. Anatomopathologic analysis of ZD lungs showed an increase of connective tissue fibers with an influx of polymorphonuclear cells. These cells and type II cells from the alveoli showed specific immunohistochemical signals for iNOS. The conclusion is that, during the development of zinc-deficiency, iNOS activity increases in lung and contributes to lung injury. Zinc deficiency implications must be taken into account to design therapies and public health interventions involving targeted zinc supplementation for high-risk subjects or certain diseases, such as asthma.
Gomez
Nidia N
NN
Fac. de Química, Bioquímica y Farmacia, Univ. Nacional de San Luis, Argentina. ngomez@unsl.edu.ar
Davicino
Roberto C
RC
Biaggio
Veronica S
VS
Bianco
German A
GA
Alvarez
Silvina M
SM
Fischer
Patricia
P
Masnatta
Lucas
L
Rabinovich
Gabriel A
GA
Gimenez
María S
MS
D000818:Animals; D001835:Body Weight; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D007150:Immunohistochemistry; D008168:Lung / Q000201:enzymology* / Q000378:metabolism; D008297:Male; D016328:NF-kappa B / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D009929:Organ Size; D018384:Oxidative Stress; D011654:Pulmonary Edema / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015032:Zinc / Q000172:deficiency*
D016328:NF-kappa B; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D015032:Zinc