Calcium antagonist verapamil prevented pulmonary arterial hypertension in broilers with ascites by arresting pulmonary vascular remodeling.

Calcium signaling has been reported to be involved in the pathogenesis of hypertension. Verapamil, one of the calcium antagonists, is used to characterize the role of calcium signaling in the development of pulmonary arterial hypertension syndrome in broilers. The suppression effect of verapamil on pulmonary arterial hypertension and pulmonary vascular remodeling was examined in broilers, from the age of 16 days to 43 days. Our results showed that oral administration of lower dose of verapamil (5 mg/kg body weight every 12 h) prevented the mean pulmonary arterial pressure, the ascites heart index and the erythrocyte packed cell volume of birds at low temperature from increasing, the heart rate from decreasing, and pulmonary arteriole median from thickening, and no pulmonary arteriole remodeling in broilers treated with the two doses of verapamil at low temperature was observed. Our results indicated that calcium signaling was involved in the development of broilers' pulmonary arterial hypertension, which leads to the development of ascites, and we suggest that verapamil may be used as a preventive agent to reduce the occurrence and development of pulmonary arterial hypertension in broilers.