Selective blockade of the vasoactive intestinal peptide (VIP) receptors affect formation and development of coronary arteries in quail embryonic heart

Abstract

We have previously demonstrated that VIP receptors are morphogenic modulators of embryonic coronary vessel tube formation in vitro. This study tested the hypothesis that a selective blockade of VIP receptors will affect formation and development of the coronary vessels in vivo. At embryonic day (ED) 5, 6, 7, and 8, a selective VIP receptor antagonist, VIP (6‐28), was injected in ovo into the vitelline vein of the Japanese quail embryos at a final concentration of 10 µmol/L. Six embryos per each ED were sacrificed 4 days after the injection and the base of their hearts was fixed in 4% paraformaldehyde/PBS, and processed for frozen or paraffin‐embedded histological cross‐sections. The serial sections through the origin of the coronary vessels were studied by H&E staining or by immunostaining with the antibodies against α‐smooth muscle actin and quail endothelium (QH1). We found that the blockade of VIP receptors did not alter the formation of left and right coronary arteries in all experimental embryos. However, when the injection was done on ED8 (the time when multiple endothelial channels penetrate the aortic wall in all three aortic sinuses), an additional coronary artery originating from a non‐coronary sinus had been detected on ED12. Furthermore, the embryos from this experimental group showed a delay in the maturation of the tunica media of coronary arteries. Our findings demonstrate that VIP receptors are involved in morphogenic modulation of coronary artery development in the embryonic quail heart.Grant Funding SourceStart‐up funding