Bronchial Submucosal Glands Research Articles

Adrenergic Stimulation of Mucus Secretion in Human Bronchi

Adrenergic agonists have been shown to stimulate secretion of airway mucus in animals; 1 Gallagher JT Kent PW Passatore M Phipps RJ Richardson PS. The composition of tracheal mucus, and the nervous control of its secretion in the cat.. Proc R Soc Lond B. 1975; 192: 49-76 Crossref PubMed Scopus (93) Google Scholar , 2 Borson DB Chinn RA Davis B Nadel JA. Adrenergic and cholinergic nerves mediate fluid secretion from tracheal glands of ferrets.. J Appl Physiol. 1980; 49: 1027-1031 PubMed Google Scholar however, evidence for a similar effect in human airways is conflicting. In two studies on human bronchial explants in vitro, adrenergic agonists had no effect on mucus glycoprotein secretion; 3 Sturgess J Reid L. An organ culture study of the effect of drugs on the secretory activity of the human bronchial submucosal gland.. Clin Sci. 1972; 43: 533-543 Crossref PubMed Scopus (90) Google Scholar , 4 Boat TF Kleinerman JI. Human respiratory tract secretions. 2. Effect of cholinergic and adrenergic agents on in vitro release of protein and mucous glycoprotein.. Chest. 1975; 67: 32-S-34S Crossref Google Scholar in a third, more recent study, mucus glycoprotein secretion was increased by α-adrenergic stimulation but not by β-adrenergic stimulation. 5 Shelhamer JH Marom Z Kaliner M. Immunologic and neuropharmacologic stimulation of mucous glycoprotein release from human airways in vitro.. J Clin Invest. 1980; 66: 1400-1408 Crossref PubMed Scopus (154) Google Scholar In these human bronchial explants experiments, however, long (2-4 hr) sampling periods were used, and so rapid, transient changes in secretion would probably have been missed. We therefore decided to re-examine the effects of α-, and of β-adrenergic agonists on mucus glycoprotein secretion in human bronchi, but with an in vitro technique that allows rapid changes in secretion to be seen. 6 Phipps RJ Nadel JA Davis B. Effect of alpha-adrenergic stimulation on mucus secretion and on ion transport in cat trachea in vitro.. Am Rev Respir Dis. 1980; 121: 359-365 PubMed Google Scholar A preliminary account of some of this work has been published. 7 Phipps RJ. Adrenergic stimulation of mucus secretion in the human bronchus.. J Physiol. 1979; 296: 44-P PubMed Google Scholar

Composition and control of secretions from tracheal bronchial submucosal glands

TRACHEAL bronchial submucosal (TBS) glands are thought to supply a significant fraction of respiratory tract fluid (RTF)1, which is critically important in cleaning the airways of the lung. In the cleaning process, cilia in the tracheal bronchial tree continuously sweep the RTF, with debris, out of the lung. But abnormalities in the physicochemical properties of the RTF may impair this clearance, resulting in fluid stagnation, infection and obstruction of the airways. Unfortunately, because of the small size and inaccessibility of TBS glands and the difficulty in collecting their uncontaminated secretions, little is known about their physiology. We have developed methods for collecting and analysing secretions from single TBS glands of the cat in vitro, and we describe here the composition and control of the fluid secreted by these glands. We have found that the composition of the secreted fluids is very similar to that of the extracellular fluid and that secretion flow rates are influenced predominantly by α-adrenergic and cholinergic agonists. In view of the well known exocrinopathy in the lethal genetic disease cystic fibrosis (CF)2, we believe these findings to have implications for pathological changes in the airways in this disease.

Immunoglobulin containing cells in the bronchopulmonary system of non-pneumonic and pneumonic calves

In an examination of the immunoglobulin containing cells in the respiratory mucosa of three-month-old non-pneumonic calves, IgA was found to be the predominant plasma cell type. In calves with cuffing pneumonia there was a marked increase in the plasma cell population in the bronchial wall and IgG1 cells became the major cell type. Similarly in calves with an exudative type of pneumonia IgG1 plasma cells were the significant cell type in the respiratory mucosa but the total number of plasma cells was similar to that found in the non-pneumonic animals. The immunohistochemical results suggest that IgA and, to a lesser extent, IgM are both transported across the mucous membrane via bronchial epithelial secretory cells and submucosal glands.

Tissue distribution of lysozyme in man.

The distribution of lysozyme (LZM) in normal human tissues was determined with the use of the immunoglobulin-enzyme (peroxidase) bridge method. LZM was detected in the following cells and tissues: secretory cells of the lacrimal gland, ductal epithelial cells of the parotid gland and the serous parts of the mixed sublingual glands, the esophageal submucosal glands, bronchial serous submucosal glands, gastric and pyloric glands, Brunner's glands of the duodenum, the Paneth cells of the small intestine, Kupffer cells of the liver and renal proximal tubular cells. In addition, LZM was also found in the mononuclear or polymorphonuclear cells of the placenta, lung, lamina propria of the small intestine, lymph nodes and spleen. This distribution of LZM is discussed in relation to its possible physiologic role in human tissues and particularly to its known antibacterial properties.

In vitro incorporation of (3H)threonine and (3H)glucose by the mucous and serous cells of the human bronchial submucosal gland. A quantitative electron microscope study.

Incorporation of [3H]threonine and [3H]glucose by the mucous and serous cells of the human bronchial submucosal gland has been studied over 8 h using, for the first time in vitro pulse labeling and electron microscope autoradiography. In assessing the autoradiographs, two methods were compared, the circle analysis and the recently described hypothetical grain analysis. Preliminary studies showed formaldehyde to be the most suitable fixative. Chemical analysis of tissue revealed that [3H]threonine was incorporated into the polypeptide moiety of the bronchial gland product and that metabolites of [3H]-glucose were incorporated into the carbohydrate. Tritiated threonine was first localized in the endoplasmic reticulum of both mucous and serous cells and later migrated to the Golgi apparatus, while metabolites of [3H]glucose localized first mainly in the Golgi apparatus. From here, both radioactive precursors were next identified in vacuoles and, finally, in secretory granules. The mucous cell incorporated strikingly more of both radioactive precursors than the serous cell. Thus, it seems that oligosaccharides of mucous and serous cell glycoproteins are synthesized mainly in the Golgi apparatus and added there to the polypeptide core which is synthesized in the endoplasmic reticulum. The relationship of the mucous cell to the serous cell is discussed. It seems that under "normal" conditions each cell represents a different line but that injury may transform a serous cell into a mucous cell.

The effect of pH on Alcian Blue staining of epithelial acid glycoproteins. II. Human bronchial submucosal gland

The effect of pH on Alcian Blue staining of sialomucins and sulphomucins in human bronchial submucosal glands has been analysed. Using Alcian Blue combined with periodic acid-Schiff, lowering the pH was associated with a decrease in the area staining with Alcian Blue and an increase in that staining with periodic acid-Schiff, save in one bronchus with a large sulphomucin content, in which an increase in the area staining with Alcian Blue was found at pH1.0. In all bronchi, an increase in the intensity of Alcian Blue staining was found at this pH. Sialomucin sensitive to sialidase was found to lose Alcian Blue staining at a higher pH than sialomucin resistant to the enzyme. Some sulphomucins stained with Alcian Blue throughout the pH range studied and some only at the more acid pH levels. At pH1.0 Alcian Blue stained only sulphomucins, thus distinguishing them from sialomucins. Alcian Blue staining combined with the high iron diamine technique has enabled three sulphate groups to be identified: one stained with high iron diamine, the other two did not, and, of the latter, one stained with Alcian Blue at pH 2.6 and1.0, and the other only at pH1.0.

An organ culture study of the effect of drugs on the secretory activity of the human bronchial submucosal gland.

1. The incorporation of tritiated glucose into bronchial gland cells enables their glycoprotein secretion to be followed by radioautography. The number of cells from which secretion is observed after 4 h of cell culture is the secretory index. 2. Large variations in secretory index were observed between the bronchi of different subjects, but the secretory index was proportional to gland size. 3. The secretory index was increased by parasympathomimetic drugs and diminished by parasympatholytic drugs, the magnitude of the effect being proportional to gland size in the former and inversely proportional in the latter case. 4. Sympathomimetic drugs, bradykinin and mucolytic drugs had no effect on the secretory index. 5. In cystic fibrosis, bronchitis and bronchiectasis gland size and not the disease process was the main determinant of the secretory index.

Secretory activity of the human bronchial mucous glands in vitro

Incorporation and discharge of radioactive glucose and threonine by the mucous and serous cells of the human bronchial submucosal gland have been studied quantitatively using organ culture. Bronchi were mostly obtained from surgical specimens. Concentration of radioactive precursor in the culture medium did not influence the speed of its passage through the cell but changed grain density in the autoradiograph. A different method of quantification was needed for each cell type. Incorporation of glucose into the mucous and serous cells was essentially similar but a little slower in the serous. Threonine appears faster throughout a cell than does glucose but again rather more slowly in serous. In some mucous cells it appears only at base and apex, seeming to be within endoplasmic reticulum and not in the secretory granules. The secretory index (percentage of mucous cells secreting in 4 hours) was similar for all material from any one bronchus. Individual variation was seen and proved to be related to gland size, the higher the gland/wall ratio the higher the secretory index. This applied to the glands from chronic bronchitis, bronchiectasis, and cystic fibrosis. The relation between gland/wall ratio and secretory tubule and cell size has been estabilished.

Quantitative distribution of various types of acid glycoprotein in mucous cells of human bronchi.

The mucous cells of human bronchial submucosal glands produce acid glycoprotein. Using histochemical techniques, four different histochemical types of acid mucin can be identified in these cells. Individual mucous cells may produce one type or one of a limited number of combinations of types.

Acinic cell tumor of the lung.A histologic and ultrastructural study

This is the first description, to our knowledge, of a primary neoplasm of the lower respiratory tract having the cytologic appearance of a salivary gland acinic cell tumor. When examined by light microscopy, the cells have cytoplasmic granules which are positive with PAS and negative with mucicarmine, alcian blue, and Masson-Fontana stains. Ultrastructurally, two cell types are seen: a dark cell resembling the normal serous cell of the bronchial submucosal gland and a light cell similar to the cells of previously reported acinic cell tumors of the parotid. It seems likely that the lesion described herein originated from the serous cell of the bronchial submucosal gland and can be designated as an acinic cell tumor analogous to that occurring in the salivary gland. Salivary gland acinic cell tumors are histologically distinctive neoplasms which may have their metastases appear more than 10 years after removal of the primary. Our patient is well nearly 2 years after lobectomy.

The tracheobronchial submucosal glands in cystic fibrosis: A qualitative and quantitative histochemical study

A quantitative histochemical investigation has been made of the types of acidic glycoprotein produced by the mucous and serous cells of the bronchial submucosal glands in patients with cystic fibrosis. No qualitative abnormalities could be identified in the types of acidic glycoproteins produced in this disease. There was a decrease in the proportion of mucous cells producing sialomucin and an increase in the proportion producing sulphated mucin, as in the case of the mucous cells of adults with bronchiectasis in the absence of cystic fibrosis. It was concluded that there was no primary abnormality in the acidic mucins produced by bronchial mucous cells in patients with cystic fibrosis and that the change in the proportion of cells producing the different acidic mucins was a secondary phenomenon related to the bronchial damage.

Acidic glycoproteins produced by the mucous cells of the bronchial submucosal glands in the fetus and child: A histochemical autoradiographic study

The adult mucous cells of the submucosal glands of the trachea and bronchus produce four varieties of acidic glycoproteins. Only one of these, the heavily sulphated type, is produced in the fetus. The percentage of mucous cells producing sulphated mucin falls, and the percentage producing sialomucin rises to the normal adult levels over the first 2–3 years of life. The predominance of sulphated mucin in the fetus is not one aspect of a general inability to produce sialomucin in fetal life, nor is it the consequence of an inactive resting phase in the mucous cell activity. The significance of these findings is discussed.

A reconstruction of the duct system and secretory tubules of the human bronchial submucosal gland.

A graphic reconstruction has been made of a submucosal gland from a normal human main bronchus, revealing a collecting duct not previously described. Ciliated respiratory epithelium dips into the gland opening to line the first part of the duct, the <i>ciliated duct</i>, and then gives way, in the <i>collecting duct</i>, to an epithelium composed of tall, columnar, eosinophilic cells containing numerous large mitochondria. This cell structure suggests that the collecting duct controls ionic and water concentration. From the collecting duct arise secretory tubules lined by mucous cells—<i>mucous tubules</i>. Tubules lined by serous cells—<i>serous tubules</i>—arise from mucous tubules either terminally or laterally.

An Experimental Study of Bronchial Glands

Patients with primary idiopathic obstructive pulmonary emphysema who had the reduction in lung volume and the bilateral bronchopulmonary denervation operation revealed marked atrophy of submucosal bronchial glands when compared with the normal and with the unoperated patient with pulmonary emphysema. In addition, there was considerable reduction of PAS positive secretions and an absence of secretion stained by Alcian blue, thus indicating less neutral mucopolysaccharides and an absence of acid mucopolysaccharides. There was also atrophy of submucosal layers of the bronchi. The submucosal bronchial glands of the domestic pig with the bronchopulmonary denervation operation showed marked atrophy when compared with normal control animals. There was a decrease in PAS positive secretions and a marked decrease in Alcian blue staining secretions from these atrophied glands. There was an appearance of goblet cells in the bronchial mucosa after bilateral bronchopulmonary denervation not found in normal control pigs without denervation. In addition, there was marked atrophy of the submucosal and mucosal layers of the bronchi after bilateral bronchopulmonary denervation.