glycogen and Airway-Obstruction

The effect of increased respiratory resistance (stenosis of the trachea) on glycogen and triglyceride levels in the diaphragm (D) and intercostal (external-IE, internal-II) muscles was studied in the rat. Tracheal stenosis resulted in a reduction of glycogen level in the muscles. For the fed rats the reductions were: D-45 and 79%, IE-14 and 30%, II-14 and 35%, 0.5 and 3 h after stenosis, respectively. For rats fasted for 24 h the reductions were: D-64 and 86%, IE-33 and 71%, II-40 and 82%, after 0.5 and 3 h respectively. The level of triglycerides in the muscles was stable during stenosis in the fed group, whereas in the fasted group it were reduced in the diaphragm by 50% after 0.5 h, and by 52% after 3 h. It is concluded that both endogenous and blood-born energy fuels are utilized by the respiratory muscles during increased resistance breathing.

Topics: Airway Obstruction; Animals; Diaphragm; Fasting; Glycogen; Intercostal Muscles; Male; Rats; Rats, Inbred Strains; Respiration; Trachea; Triglycerides

The lung, like other viable organs, requires the adequate supply of oxygen and metabolic substrates for its functional and structural integrity. Therefore, we studied the metabolic and ultrastructural consequences in the canine lung following bronchial and/or pulmonary arterial occlusions. The results indicate that the lung can maintain its bioenergetic levels for 5 hours with either the ventilation or perfusion alone. Ultrastructural changes appear to precede metabolic alterations measured. When both the ventilation and perfusion were interrupted, rapid biochemical and structural deteriorations occurred, whereas the combinations of alveolar obliteration and hypoxemia, induced with low F102, produced intermediate damage. The implications of these findings on the pathogenesis and evolution of acute respiratory distress syndrome, on the lung preservation for transplantation, and on the rationale for membrane oxygenator support are discussed.

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Airway Obstruction; Animals; Arterial Occlusive Diseases; Blood Gas Analysis; Blood Glucose; Dogs; Glycogen; Hypoxia; Lactates; Lung; Postoperative Complications; Pulmonary Artery; Pulmonary Edema; Respiratory Distress Syndrome; Ventilation-Perfusion Ratio

Topics: Airway Obstruction; Asphyxia; Electrocardiography; Glycogen; Heart Rate; Manometry; Metabolism; Myocardium; Pathology; Pulse; Rabbits; Research; Sympathomimetics; Trachea