Paraquat poisoning: an experimental model of dose-dependent acute lung injury due to surfactant dysfunction

Abstract

Since the most characteristic feature of paraquat poisoning is lung damage, a prospective controlled study was performed on excised rat lungs in order to estimate the intensity of lesion after different doses. Twenty-five male, 2-3-month-old non-SPF Wistar rats, divided into 5 groups, received paraquat dichloride in a single intraperitoneal injection (0, 1, 5, 25, or 50 mg/kg body weight) 24 h before the experiment. Static pressure-volume (PV) curves were performed in air-and salinefilled lungs; an estimator of surface tension and tissue works was computed by integrating the area of both curves and reported as work/ ml of volume displacement. Paraquat induced a dose-dependent increase of inspiratory surface tension work that reached a significant two-fold order of magnitude for 25 and 50 mg/kg body weight (P<0.05, ANOVA), sparing lung tissue. This kind of lesion was probably due to functional abnormalities of the surfactant system, as was shown by the increase in the hysteresis of the paraquat groups at the highest doses. Hence, paraquat poisoning provides a suitable model of acute lung injury with alveolar instability that can be easily used in experimental protocols of mechanical ventilation. Correspondence

Paraquat (PQ)-induced pulmonary fibrosis increases exercise metabolic cost, reducing aerobic performance in rats

“…2). In other studies (Rocco et al, 2003;Silva et al 1998), data from the area of lung collapse were used as an indicator of the degree of pulmonary injury. In the chronmaintains the alveolar collapse, thereby reducing lung ventilation and decreasing gas exchange.…”

“…In the chronmaintains the alveolar collapse, thereby reducing lung ventilation and decreasing gas exchange. The reduced lung volume and compliance result in hypoxemia and increased work of breathing (Silva and Saldiva, 1998;Kao et al, 1999), impairing physical performance during exercise (Hansen and Wasserman, 1996).…”

“…It is highly toxic to humans and animals, accumulating mainly in the lungs, liver, kidneys and heart. This herbicide has been widely used as an experimental model to study lung injury, especially diffuse alveolar damage, due to its low cost, rapid effect and simplicity of administration (Rocco et al, 2003;Silva and Saldiva, 1998). Moreover, the mecha--herbicide (Dasta, 1978).…”

Effect of fly ash on surface tension of few liquids

“…Once escaped in the air, hyphae are covered with hydrophobic film (Wostan and Willey, 2000). The surface tension of lung dynamics is explained by Silva and Saldiva (1998), where they stated that the lung dynamic behavior is possible due to surface tension. And injury is caused due to increase in surface tension eg.…”

Glycogen content is affected differently in acute pulmonary and extra-pulmonary lung injury

“…7 Paraquat undergoes redox cycling, which leads to the production of reactive oxygen species (ROS), causing disruption of pro-oxidant/ antioxidant balance. 8 Its cytotoxic effect may differ depending on the location of the injury -whether occurring in the lungs (ALI-P) or other tissue (ALI-EX).…”