Effect of Endothelin-1 on Pulmonary Hypertension Syndrome (Ascites) Broilers

摘要

Two experiments were conducted to evaluate the effect of intravenous endothelin-1 (ET-1) on pulmonary arterial pressure (PAP) and pulmonary hypertension syndrome (PHS) morbidity in broilers. Two hundred seventy 1-d-old Arbor Acre commercial broiler chicks were randomly allocated into two groups, forty in the first group and two hundred thirty in the second group. In experiment 1, the group of 40 (28 d of age) broilers was randomly divided into 5 groups (T_0, T_1; T_2, T_3, and T_4) with 8 replicates each, infused intravenously with different dose of ET-1 (0, 24, 120, 240, and 360ng/kg BW, respectively), and the mean pulmonary arterial pressure (mPAP) was measured from time 0 to 30 min. The mPAP decreased immediately from time 0 to 0.5 min and then began to increase from time 0.5 to 5 min when the broEers were injected with ET-1 24, 120, and 240ng/kg BW. When the broilers were injected with ET-1 360ng/kg BW, the mPAP decreased immediately from time 0 to 0.5 min but increased from time 0.5 to 10 min. In experiment 2, the other two hundred thirty broilers were divided into four groups: a control group (group C, 50 broilers), two injection groups (group A and B, 60 broilers each) that intravenously injected with 240, 360ng/kg BW ET-1, respectively, and one group (group D, 60 broilers) exposed to cool temperatures (10 to 14℃). The PHS morbidity of group A was higher than that of group C but lower than group B and group D. The right/total ventricular weight ratio (RV/TV) and mPAP were higher in group A, B and D than in group C. There was the same tendency of the values of packed cell volume (PCV) and plasma nitric oxide (NO) when compared group A, B, and D with group C. The results of this study suggested that ET-1 increased PAP directly, leaded to pulmonary hypertension (PH), right ventricular hypertrophy and increased morbidity of PHS in broilers.