Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress

Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g were submitted to different stressors (variable stress, N = 7) or repeated restraint stress for 15 (N = 10) or 40 days (N = 6) and compared to control groups (N = 10 each). Lipid peroxidation levels were assessed by thiobarbituric acid reactive substances (TBARS), and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. Chronic variable stress induced a 51 percent increase in oxidative stress in lungs (control group: 0.037 ± 0.002; variable stress: 0.056 ± 0.007, P < 0.01). No difference in TBARS was observed after chronic restraint stress, but a significant 57 percent increase in TRAP was presented by the group repeatedly restrained for 15 days (control group: 2.48 ± 0.42; stressed: 3.65 ± 0.16, P < 0.05). We conclude that different stressors induce different effects on the oxidative status of the organism.

Edema pulmonar pos-descompressao- relato de um caso. / Pulmonary edema post re-expansion: report of a case

E apresentado o caso de um paciente de 49 anos que teve edema pulmonar apos esvaziamento rapido de derrame pleural. Paciente apresentava volumoso derrame pleural no hemitorax esquerdo, de origem tuberculosa, o qual foi aspirado rapidamente, em um total de 2,5 1, de cor amarelo-citrino. Seis horas apos ele comecou a apresentar dispneia; o raio X de torax deste momento mostrava areas de consolidacao na metade inferior do pulmao e seu PaO2 era 49 mmHg.Foi aplicada uma ampola de furosemida EV e 60 horas apos o inicio de quadro o raio X de torax apresentava-se praticamente normal e PaO2 era 70 mmHg