Effect of Vanadium on Splenocyte Apoptosis in Broilers

Abstract

A total of 420 one-day-old healthy broilers were divided into six groups. There were 70 broilers in each group. The broilers were fed on a corn-soybean basal diet as a control diet (vanadium 0.073 mg/kg) or the same diet amended to contain 5 mg/kg, 15 mg/kg, 30 mg/kg, 45 mg/kg and 60 mg/kg vanadium supplied as ammonium metavanadate for 42 days. When compared with those of the control group, the mitochondrial injury of splenocytes and more apoptotic splenocytes with condensed chromatin with C-shaped, horseshoe-like, petal-shaped or crescent were ultrastructurally observed in the spleen in the 30 mg/kg, 45 mg/kg and 60 mg/kg groups. As measured by flow cytometry (FCM), the number of apoptotic splenocytes was significantly increased in the 15 mg/kg, 30 mg/kg, 45 mg/kg and 60 mg/kg groups. Immunohistochemical tests showed that number of positive splenocytes containing Bax and caspase-3 protein was increased, and number of positive splenocytes containing Bcl-2 protein was decreased in the 15 mg/kg, 30 mg/kg, 45 mg/kg and 60 mg/kg groups. It was concluded that dietary vanadium in excess of 15 mg/kg could result in splenocyte apoptosis in broilers. Splenocyte apoptosis was closely related to mitochondrial injury and changed expression of apoptogenic proteins induced by vanadium.