EFFECT OF ALPHA-TOCOPHEROL ON ANTIOXIDANTS, LIPID-PEROXIDATION, AND THE INCIDENCE OF PULMONARY-HYPERTENSION SYNDROME (ASCITES) IN BROILERS

Research has demonstrated a compromised antioxidant capacity in broile rs with pulmonary hypertension syndrome (PHS). Thus, the objective of the present study was to assess the effects of vitamin E on PHS-induce d mortality, tissue antioxidants, and plasma lipid peroxides in male b roilers. Control broilers were provided normal ventilation but others, maintained under low ventilation conditions to induce PHS, were rando mly assigned to nonimplanted (NI), placebo (PL), or vitamin E (VE) imp lanted groups. The VE implant released a total of 15 mg of alpha-tocop herol from 0 to 3 wk of age. Tissues and blood samples were obtained a t 3 and 5 wk of age from birds with (PHS+) and without (PHS-) PHS. Fiv e-week PHS cumulative mortality was lowered by alpha-tocopherol with m ortality rates of 3.6, 4.2, 11.9, and 11.8%, for Controls, VE, NI, and PL groups, respectively. The PHS+ birds exhibited lower body weights, higher hematocrit, right ventricular hypertrophy, lower alpha-tocophe rol and glutathione (GSH) concentrations in liver and lung, as well as indicators of oxidative stress, including elevated plasma lipid perox ides and lower oxidized GSH in Liver and erythrocytes, at 5 wk of age. All birds exhibited lower erythrocyte catalase activity at 5 than at 3 wk of age. An improved antioxidant capacity was observed in VE birds , including higher liver and lung cr-tocopherol at 3 and 5 wk, higher liver GSH at 3 wk, and lower plasma lipid peroxide values at 5 wk of a ge. Direct correlations observed between body weight and plasma lipid peroxides at 3 wk (r = .45) and between right ventricular hypertrophy and plasma lipid peroxides at 5 wk (r = .48), suggests that lipid pero xidation plays a role in the etiology of PHS. The results indicate tha t the VE implant was effective in lowering PHS-induced mortality in br oilers apparently by attenuating processes leading to lipid peroxidati on.