Macro- and microscopic characteristics of the glands of the human trachea and main bronchi in postnatal ontogenesis

By means of the macro-microscopical method 68 preparations of the trachea and main bronchi, obtained from persons perished and died at the newborn age up to 90 years and having not any disease of the respiratory pathways by the time of death have been studied. The glands in the walls of these organs are adapted to the surrounding structures and have various topography in the cartilagenous and membranous parts of the trachea and main bronchi. The ductal openings in the membranous part demonstrate a regular longitudinal orientation. Despite the fact that during human life the sizes of the trachea and main bronchi increase, the amount of the glands during the postnatal ontogenesis remains nearly at the same or about the same level. With age, the density of the ductal opening arrangement per 1 cm2 of the mucosal membrane surface changes noticeably. Comparing with the newborn age, in the old age this parameter decreases nearly by 4 times.     

Bioelectric properties and ion flow across excised human bronchi

Bioelectric properties and ion transport of excised human segmental/subsegmental bronchi were measured in specimens from 40 patients. Transepithelial electric potential difference (PD), short-circuit current (Isc), and conductance (G), averaged 5.8 mV (lumen negative), 51 microA X cm-2, and 9 mS X cm-2, respectively. Na+ was absorbed from lumen to interstitium under open- and short-circuit conditions. Cl- flows were symmetrical under short-circuit conditions. Isc was abolished by 10(-4) M ouabain. Amiloride inhibited Isc (the concentration necessary to achieve 50% of the maximal effect = 7 X 10(-7) M) and abolished net Na+ transport. PD and Isc were not reduced to zero by amiloride because a net Cl- secretion was induced that reflected a reduction in Cl- flow in the absorptive direction (Jm----sCl-). Acetylcholine (10(-4) M) induced an electrically silent, matched flow of Na+ (1.7 mueq X cm-1 X h-1) and Cl- (1.9 mueq X cm-12 X h-1) toward the lumen. This response was blocked by atropine. Phenylephrine (10(-5) M) did not affect bioelectric properties or unidirectional ion flows, whereas isoproterenol (10(-5) M) induced a small increase in Isc (10%) without changing net ion flows significantly. We conclude that 1) Na+ absorption is the major active ion transport across excised human bronchi, 2) Na+ absorption is both amiloride and ouabain sensitive, 3) Cl- secretion can be induced by inhibition of the entry of luminal Na+ into the epithelia, and 4) cholinergic more than adrenergic agents modulate basal ion flow, probably by affecting gland output.     

Blood supply of the trachea and bronchi in the rat

Existence of longitudinal and circular arterio-arterial anastomoses are stated, as well as various ways of outflow from the veins of the organs studied; this demonstrates essential compensatory abilities of this bed in blood supply regulation and draining at inflow and outflow from the microcirculatory system bed. Different topography of the arterial sources, venous plexuses, capillary fields allows to suppose different histophysiology of the tracheal zones mentioned: the anterior (laryngotracheal), middle and posterior (bifurcational). For the tracheal microcirculatory bed, metamerically repeated microcirculatory areas are peculiar. Distribution of the bronchial arteries takes place up to the terminal bronchi. In the area of the latter, anastomoses of the bronchial vessels with the pulmonary artery are observed.     

Cryotherapy for advanced carcinoma of the trachea and bronchi.

Cryotherapy was used to relieve symptoms in 75 patients suffering from advanced carcinoma of the trachea or bronchi. In all patients surgical resection, radiotherapy, or chemotherapy had been tried and been unsuccessful or had been thought to be unsuitable because of the patients'' poor general condition. In cryotherapy the intraluminal tumour was frozen through a Stortz bronchoscope. Localised necrosis increased the patency of the lumen of the trachea or bronchi, resulting in relief of symptoms. Cryotherapy is effective and easily performed and causes the patient little discomfort.     

The innervation of the trachea and extrapulmonary bronchi of the mouse

Summary In the mouse, nerves were located throughout the trachea and extrapulmonary bronchi in both the smooth muscle and the connective tissue. However, no nerves were found within the epithelium. In the smooth muscle there were large numbers of nonmyelinated nerves. These were usually en passant elements but varicosities containing small mitochondria and vesicles were also seen; these axons sometimes appeared to be efferent to the muscle.Unilateral cervical vagotomy reduced the numbers of nerves in the muscle of the trachea and ipsilateral primary bronchus, suggesting that they were afferent. The intramuscular nerves were characterized in terms of their complement of cytoplasmic organelles; in particular nerves containing many mitochondria disappeared following vagotomy.Pretreatment of mice with 5-hydroxydopamine to accentuate the electron-opacity of catecholamine-containing granules resulted in 3.5% of the nerves within tracheal muscle showing such granules.The afferent nerves of the smooth muscle may be complex branching structures with many varicosities. The absence of epithelial nerves may be related to the absence of the cough reflex in the mouse.     

Surrounding structures affect pressure-diameter behavior of excised dog bronchi

The effects of adjacent large blood vessels, fibroelastic membrane, and parenchyma on pressure-diameter (P-D) behavior of intrapulmonary bronchi were studied in five dog lung lobes. Central lobar airways were inflated separately by blocking all branches with beads and inflating the distal lobar air spaces via pleural capsules. After bronchial P-D curves were obtained at fixed pleural pressures (Ppl) of -30, -10, and -5 cmH2O, the P-D properties of the isolated bronchi were measured in each of four stages of dissection: 1) lobar artery and vein were left attached to the bronchus, but parenchyma was removed to within 1-2 mm of the limiting membranes; 2) all remaining parenchyma was carefully removed; 3) the large vessels were removed, leaving the bronchial fibroelastic membrane intact; and 4) the fibroelastic membrane was peeled from the bronchus. From stage 1 it was deduced that in the intact lobes, peak peribronchial parenchymal stress (Px) averaged -29.2 cmH2O at Ppl = -30 cmH2O). In stage 2 bronchial recoil was reduced only approximately 5%. The major decrease (approximately 35%) occurred in stage 3, indicating that interaction between vessels and bronchi contributed significantly to bronchial stiffness. A final decrease of approximately 10% was seen in stage 4. We conclude that Px in the intact state is similar to Ppl at a transpulmonary pressure of 30 cmH2O and that stages 1 or 2 may provide a better basis for estimating Px than the commonly employed bronchus free of vessels and tissue.     

Effect of beta-adrenoblockaders on the smooth muscles of the trachea and bronchi

It has been shown in experiments on anesthetized guinea-pigs that (+/-) and (+) propranolol produced a dose-dependent increase in the resistance of the air ways. Meanwhile oxprenolol, trimepranol and atenolol had a poor bronchoconstrictor effect, and labetalol evoked no changes in the tone of the bronchi. On an isolated trachea of the guinea-pig both forms of propranolol, as well as trimepranol and oxprenolol produced contractions, atenolol did not cause any changes in the tone of the smooth muscles, while labetalol made the smooth muscles relax. It has been also demonstrated on an isolated trachea that pretreatment with atropine, diphenhydramine, and diethylamide of lysergic acid did not lead to any noticeable changes in the bronchoconstrictive action of propranolol. At the same time verapamil and Ca2+-free Krebs solution reversed the propranolol effect.