The Microcirculation of the Tracheal Mucosaa

We used scanning electron microscopy to count the number of mucous gland openings in the tracheae and lower portion of the larynges of the rat, guinea pig, hamster, mouse and rabbit. Cells of the airway surface epithelium were removed by protease digestion better to visualise the gland openings. The distribution of glands was further studied by conventional histology and by PAS\Alcian blue staining of whole mounts. In all rodent species, gland openings in the larynx occurred with a frequency of 1-2 per mm#. Mice had no gland openings in their tracheae, and hamsters, only a handful. Rat tracheae contained 126p42 gland openings (p..; n l 6) at a frequency of " 0n6 per mm# at the top of the trachea and " 0n15 per mm# at the bottom. Guinea pig tracheae contained 153p90 gland openings (p..; n l 5), with 54 % being in the top 40 % of the trachea. In both rat and guinea pig, tracheal glands were found in the ventral aspect between the cartilaginous rings, and were absent from the dorsal membranous portion. Gland openings in most species were simple circles of " 50 µm diameter. However, glands in the rat trachea generally opened obliquely into shallow (" 20 µm deep) oval troughs (" 150i75 µm), which had their long axes oriented from head to tail. In the rabbit, there was no evidence of tracheal or laryngeal glands histologically. However, the tracheal and laryngeal surfaces contained numerous pits (" 30 µm diameter) distributed evenly over and between cartilages at a frequency of " 4 per mm#. These may correspond to the ' nests ' of goblet cells described by others.

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“…12). This has also been reported by others (Sobin et al 1963) using silicone rubber casts of the tracheal vasculature.…”

Section: supporting

confidence: 85%

Distribution of tracheal and laryngeal mucous glands in some rodents and the rabbit

et al. 2001

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“…It may be argued that epithelium-smooth muscle interactions would be more pronounced and more important in vivo. However, in vivo any released epithelial factor must pass a well-perfused and copious network of microvessels in the mucosa/submucosa (Sobin et al, 1963;Laitinen et al, 1987) and hence would much less readily reach the deeper-lying muscle in vivo than in vitro. This reasoning does not exclude the possibility that airway epithelial factors have very important regulatory functions in health and disease.…”

Section: Relaxant Effectsmentioning

confidence: 99%

“…However, it seems less likely that epithelial factors would directly affect airway smooth muscle that, similar to the uterine preparation discussed above (Whalley, 1978), is separated from the epithelium by a layer of tissue that is both thicker than the internal elastic lamina, separating endothelial cells from vascular smooth muscle, and contains a very profuse network of microvessels (Sobin et al, 1963;Laitinen et al, 1987). Hence, the airway epithelium may not be comparable to the vascular endothelium as regards possible influence on smooth muscle tone.…”

Section: Introductionmentioning

confidence: 99%

The epithelium and the pharmacology of guinea‐pig tracheal tone in vitro

Lundblad

Persson

1988

British J Pharmacology

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“…3 In some experimental animals, such as as vesiculo-vacuolar 0.1 m wide channels across thin parts of endothelial cells. 10 Through the gaps/holes in the guinea-pig, the nose and trachea 4 are similar to man, whereas more peripherally rodents have few the venular wall non-sieved plasma would be moved subepithelial vessels but a rich peribronchial microby the hydrostatic pressure gradient into extravascular vascular bed.…”

Section: Introductionmentioning

confidence: 99%