Origin, distribution, and blood flow of bronchial circulation in anesthetized sheep

Abstract

This anatomical-physiological study was undertaken to determine the suitability of the sheep for studies of the bronchial circulation. We designated the terminal portion of the bronchoesophageal artery, which runs to the trachea at the carina, as the "carinal" artery. Postmortem injections of india ink (9 sheep) and Batson's solution (4 sheep) into the carinal artery showed that the carinal artery supplied the bronchi of all lobes except the right apical lobe; the mass of the lung containing bronchi perfused represented 88 +/- 1% of total lung mass. Communications were also found between branches of the carinal artery and branches of the systemic arteries supplying the visceral pleura. In three of six sheep, the carinal artery wedge pressure measured in vivo indicated that patent collaterals were present, but that their incidence is variable. In additional postmortem casts of the aorta made in four sheep after ligation of the carinal artery, the bronchial microcirculation was not entered by the perfusing medium. These data indicate that the collaterals do not contribute significantly to bronchial blood flow and that the carinal artery is the major source of bronchial blood flow in the sheep. In 19 sheep, carinal artery flow, measured electromagnetically, was 0.46 +2- 0.09 ml . min-1 . kg body wt-1. Bronchial blood flow normalized for the weight of the lobes in which bronchi perfused by the carinal artery were located was 3.97 +/- 0.48 ml . min-1 . 100 g lung-1 (n = 11); carinal artery blood flow was 0.39 +/- 0.03% of cardiac output (n = 5). During the 90 min of observation, at normal aortic blood pressure (103 +/- 3.4 Torr), carinal artery blood flow was stable. In conclusion, determination of carinal artery blood flow affords a reliable approach to the bronchial circulation in the sheep.

Role of anti-L-selectin antibody in burn and smoke inhalation injury in sheep

“…Within 20 min of smoke inhalation, the bronchial blood flow increases 10-to 15-fold. Magno and Fishman (10) showed that the tracheal bronchial artery is one of the major sources of blood to the lung. We have also reported that occlusion of the bronchial artery prevented the increase in pulmonary transvascular fluid flux seen with inhalation injury (3,12).…”

Pulmonary Epithelium: Cell Types and Functions

“…These primary airway then branch into a series of intra-pulmonary bronchial and bronchiolar airway. Both the diameter and the length of each airway branch decrease progressively from the trachea to the periphery, where the terminal bronchioles are the most distal conducting airway (Magno and Fishman, 1982). In rodents, these bronchioles lead directly to alveolar ducts, whereas in humans and monkeys, a region of transitional respiratory bronchioles with characteristics of both bronchioles and alveoli exists between the bronchioles and the alveoli of the gas exchange area (Tyler, 1983).…”

Acute alveolar hypoxia increases bronchopulmonary shunt flow in the dog.

“…Systemic hypoxemia has been reported to increase (18)(19)(20) or decrease (21,22) total bronchial flow, and systemic hypercarbia has been reported to increase (12,19,22), not change (5), or decrease (21) bronchial flow.…”