[Morphologic and biochemical kinetics of the pathogenesis of acute lung injury by endotoxin in rats].
OBJECTIVE
To highlight the intervention sequence of cells and their products (RO degree and NO) involved in the pathogenesis of lung injury caused by the instillation of endotoxin in rats.


METHODS
An experimental comparative study in rats.


METHODS
The experiments were performed using intratracheal instillation of endotoxin in rats (5 mg/kg in 0.125 ml of saline solution). Untreated rats or those instilled with saline solution alone formed the control group. All animals were sacrificed 12, 24 and 48 hours after instillation and the following studies were performed on both lungs: 1) morphological study (optical and electronic); 2) assay of lung MDA; 3) NADPH-diaphorase evaluation using a histochemical method.


RESULTS
Lung damage evolves gradually over 48 hours. After the first 12 hours, neutrophil granulocytes were present in the lung capillaries together with monocytes; monocytes were also present in the interstitium. During the following hours, monocytes differentiated into macrophages and, once activated, the granulocytes passed into the interstitium. The parenchyma appears to be extensively altered. Tissular MDA gradually increases until it reaches a maximum level (p < 0.01 vs basal) at 48 hours. Positivity for NADPH-d in macrophage and/or fibroblastic cells was evident after 24 hours and increased after 48 hours.


CONCLUSIONS
Acute lung injury caused by endotoxin involves both NO and RO degree. Their production is related to different cell types and follows slightly different kinetic.
Istituto di Anestesiologia e Rianimazione, Università degli Studi, Firenze.
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Adembri
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Domenici-Lombardo
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Meucci
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Sardu
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Papucci
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Forzini
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Novelli
D000208:Acute Disease; D000818:Animals; D004731:Endotoxins / Q000633:toxicity*; D008171:Lung Diseases / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D009252:NADPH Dehydrogenase / Q000378:metabolism; D051381:Rats
D004731:Endotoxins; D009252:NADPH Dehydrogenase
Cinetica morfologica e biochimica della patogenesi del danno polmonare acuto da endotossina nel ratto.