Resumen de Detailed arrangement of the bronchial arteries in the Wistar rat: A study using vascular injection and scanning electron microscopy.
A.S. Pereira, A.P. Aguas, P.G. Ferreira, N.R. Grande, A.C. Silva
We have used vascular castings, light microscopy coupled with tracers, and scanning electron microscopy to define the detailed anatomy of the bronchial arteries in the Wistar rat, a rodent often used in experimental research on lung disorders; namely in those that involve vascular alterations. We found that there are two bronchial arteries in the Wistar rat and that they have a cranial origin, either from the subclavian arteries or from their primary branches. The left bronchial artery was always originated from the internal thoracic artery, ran between the thoracic aorta and the left cranial vena cava and offered branches to the thymus, trachea and esophagus. The right bronchial artery was of variable origin, and was located between the right cranial vena cava and the trachea; it gave off branches to the right cranial vena cava, phrenic nerve, trachea, esophagus and, seldomly, to the mediastinic-pericardial pleura, myocardium and caudal vena cava. In more than half of the rats, there were anastomoses between the bronchial and pulmonary arteries. The histological organization of rat bronchial arteries was different from those of humans, suggesting that there are differences in the resistance to blood flow between the two species. Scanning electron microscopy revealed that the bronchial arteries formed two plexuses surrounding the intrapulmonary airways and also supplied the vasa vasorum of pulmonary arteries and veins. We conclude that there are important differences in the arrangement and structure between bronchial arteries in humans and rats and that this should be taken into account whenever data from experimental studies are to be extended to humans.
