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

In experiment, the effect of repeated inhalations of mineral water aerosol on the airway epithelium was investigated. Six rabbits inhaled mineral water for 10 min 5× in the course of 5 days, seven animals served as untreated controls. The tracheal mucous membrane was processed using standard methods of transmission electron microscopy; the results were evaluated quantitatively. In paraffin-embedded material, the methods of conventional and lectin histochemistry were employed. Due to the contact with mineral water aerosol, the goblet cells were overstimulated and the mechanism of secretion was accelerated. The exhausted goblet cells represented 66 ± 2%. High level of goblet cells' stimulation resulted in changes in their distribution in the epithelium. Small intraepithelial mucous glands were formed by 33 ± 4% of goblet cells. Goblet cells containing neutral glycoconjugates disappeared. A significant (α = 0.01) increase in number of cells producing acid sulphated glycoconjugates was accompanied with significant (α = 0.01) decrease in cells containing α(2-3) sialylated ones. In the ciliated cells, slight apical blebbing and mild signs of pathological alteration of the deeper portions of their cytoplasm were noticed. In the ciliary border, the mean number of cilia was 7.2 ± 0.3/m 2 . The altered kinocilia represented 5.8 ± 1.4%. These values were slightly but significantly (α = 0.01) lower compared with controls. As morphological signs of impaired self-cleaning ability of the airway epithelium, clumps of condensed mucus were discovered in the area of the slightly impaired ciliary border. According to our classification of the airway epithelium injury, the degree of damage to the tracheal epithelium was mild to moderate. Airways, ultrastructure, lectin histochemistry, glycoconjugates, ciliated cells, goblet cellsIn our preceding study, we demonstrated the effect of a single 10-min inhalation of mineral water on the airways. In the tracheal epithelium, the secretory elements were overstimulated and changes in the character of their glycoconjugates (GCs) were recorded . In clinical practice, whole series of inhalations are usually prescribed. Therefore, we decided to investigate also the effect of repeated inhalations of mineral water aerosol on the airway epithelium. Materials and MethodsIn our experiments, 13 SPF New Zealand White male rabbits (Charles River Deutschland, Sulzfeld, Germany) of body weight 1,500 -3,000 g, 3 -7 months of age were used. The animals were kept in our breeding facility under standard conditions, fed with complete granulated mixture TM-MaK 1. Seven animals served as untreated controls. For administration of mineral water aerosol, a plastic cage connected with the inhalation device PARI Master and nebuliser PARI LL (Pari GmbH, Starnberg, Germany, medium diameter of produced droplets 3.1 µm, total output 0.6 g/min) was used. The rabbits inhaled an aerosol of natural hypertonic iodinated spring water (osmolarity 331 mOsm, pH 6.48) for 10 min 5× in the course of 5 days. Chemical composition of ...

Section: Discussionsupporting

confidence: 93%

Tracheal Epithelium of Rabbits after Repeated Inhalations of Mineral Water Aerosol

Konrádová¹,

Vajner²,

Uhlı́k³

et al. 2001

“…The change towards dominance of acidic sulphated glycoconjugates was in accordance with studies of many authors on the influence of some noxae affecting the terminal glycosylation (Lamb and Reid 1972;Jones and Reid 1978;Damjanov 1987;Jeffery et al 1992). This tendency was strongly confirmed in our previous papers (Vajner 1998;Vajner et al 2000) as a result of administration of some bronchospasmolytic drugs or a high dose of acetylcholine.…”

Section: Discussionsupporting

confidence: 74%

“…On the other hand, the cells of the rabbit terminal bronchiole revealed only mild signs of pathological alteration after oral administration of ambroxol and the secretory activity of Clara cells did not differ from that found in controls (Uhlík et al in press). Lamb and Reid (1972) and Damyanov (1987) deduced a common tendency to the decrease of sialylated glycoconjugates and the increase of sulphated ones as the reaction to any alteration of the tracheal epithelium.To complete the study, changes of the glycoconjugate content of the tracheal goblet cells were studied under the same experimental conditions using both conventional and lectin histochemistry. …”

mentioning

confidence: 99%

Mucin Histochemistry of Tracheal Goblet Cells after Oral Administration of Ambroxol

Vajner¹,

Konrádová²,

Uhlı́k³

et al. 2001

Vajner L., V. Konrádová, J. Uhlík, J. Zocová: Mucin Histochemistry of Tracheal Goblet Cells after Oral Administration of Ambroxol. Acta Vet. Brno 2001, 70: 9-13. Previous studies on the effect of various mucolytic drugs on the tracheal epithelium ultrastructure revealed ambroxol as the most harmful one. To complete these studies, we decided to evaluate the effect of ambroxol on the glycoconjugate content in the secretion of tracheal goblet cells.Using the methods of both conventional and lectin histochemistry, the percentage of tracheal goblet cells containing various glycoconjugates was evaluated. Twenty minutes after oral administration of 7.5 mg of ambroxol, goblet cells containing neutral glycoconjugates disappeared from the rabbit tracheal epithelium. Among goblet cells containing acidic glycoconjugates, the percentage of sialylated glycoconjugate-containing ones slightly decreased compared with control healthy rabbits.Oral administration of ambroxol only slightly affected the composition of glycoconjugates contained in goblet cells of the tracheal epithelium in rabbits. Tracheal goblet cells, conventional and lectin histochemistry, mucolytic drug ambroxol, rabbitAmbroxol, the most frequently used mucolytic agent in clinical practice, affects both ciliated and secretory cells in the respiratory system. It stimulates ciliary activity as well as incorporation of precursors into phospholipids in granular pneumocytes causing thus a decrement of mucus adhesion to the hypophase. According to pharmacological studies, it facilitates incorporation of hydrolytic enzymes into lysosomes of the airways' secretory cells. Activation of these acidic mucopolysaccharide-degrading enzymes leads to a decrease of the sputum viscosity (·míd and Holcát 1994). In our previous studies, reactions of the rabbit tracheal epithelium to oral administration of a single therapeutic dose of 6 various mucolytic drugs were compared. The adverse effect of ambroxol was the most pronounced (Konrádová et al. 1985ab;1996a). More than ninety seven per cent of the goblet cells had been stimulated to discharge their mucus. They either released their secretion from apical granules and/or detached packets of granules (14.5%) or were completely evacuated (83%) and only remnants of their degenerated cytoplasm were left in the epithelium. On the other hand, the cells of the rabbit terminal bronchiole revealed only mild signs of pathological alteration after oral administration of ambroxol and the secretory activity of Clara cells did not differ from that found in controls (Uhlík et al. in press). Lamb and Reid (1972) and Damyanov (1987) deduced a common tendency to the decrease of sialylated glycoconjugates and the increase of sulphated ones as the reaction to any alteration of the tracheal epithelium.To complete the study, changes of the glycoconjugate content of the tracheal goblet cells were studied under the same experimental conditions using both conventional and lectin histochemistry.

“…The presence of neutral and acidic sulphated and acidic sialylated glycoconjugates (GCCs) was widely evidenced in many species including humans (Lamb and Reid 1972;Jones and Reid 1978;Jacob and Poddar 1982;Spicer et al 1983;Castells et al 1990Castells et al , 1991Castells et al , 1992Castells et al , 1994Jeffery et al 1992;K im et al 1997). Damjanov (1987) stressed the differences in the GCC composition among individual species.…”

Section: Airways' Epithelium Cholinergic Stimulation Glycoconjugatementioning

confidence: 99%

The Effect of Intravenously Administered acetylcholine on the Glycoconjugate Composition on Goblet Cells of the Tracheal Epithelium in Rabbits

Vajner¹,

Uhlı́k²,

Konrádová³

et al. 2000

To evaluate the influence of cholinergic stimulation on the composition of glycoconjugates in goblet cells, we studied the tracheal epithelium of rabbits 5 minutes and 20 minutes after i.v. administration of acetylcholine in doses 0.1 mg and 0.5 mg, respectively. Using both conventional and lectin histochemistry, we compared the percentage of tracheal goblet cells containing neutral glycoconjugates to those containing total acidic glycoconjugates, sulphated acidic glycoconjugates, and sialylated acidic glycoconjugates. A conspicuous increase in percentage of neutral glycoconjugates-containing goblet cells and a decrease of sialylated glycoconjugatescontaining goblet cells occurred as early as 5 minutes after the administration of the lower dose and were recorded 20 minutes post exposure, too. Five minutes post exposure, the higher dose evoked a decrease in percentage of both neutral-and sialylated glycoconjugates-containing goblet cells. Twenty minutes after the administration of the higher dose, percentage of all studied elements reached values similar to those found in the lower dose group. The cholinergic stimulation did not cause total disappearance of both neutral-and sialylated glycoconjugates-containing goblet cells. Only the reaction of goblet cells 5 minutes after the administration of the higher acetylcholine dose differed quantitatively from the reactions in remaining experimental groups. Airways' epithelium, cholinergic stimulation, glycoconjugates, lectin histochemistryIn our previous studies, we demonstrated that the goblet cells (GC) in the rabbit tracheal epithelium were overstimulated and damaged due to the intravenous (i.v.) administration of acetylcholine. An apocrine type of secretion and also chain exocytosis were found after the administration of both doses of acetylcholine. Twenty minutes after the administration of 0.5 mg of acetylcholine, the degeneration of GC evoked massive differentiation of new secretory elements (Konrádová et al. 1996ab). Similar reaction of GC was also described by Specian and Neutra (1980) in the tissue culture of intestinal GC, and by Newman et al. (1996) in the tracheal epithelium of guinea pigs. Tokuyama et al. (1990) andFung et al. (1992) confirmed the stimulating effect of vagal control to the secretion of airways' GC and submucosal glands. Ramnarine and Rogers (1994) stressed non-adrenergic, non-cholinergic (NANC) neural mechanisms, coworking with neurogenic acetylcholine as "the secretion fine tuning". A direct effect of acetylcholine on tracheal secretory elements was further confirmed as a dose-dependent in studies by Kamijo et al. (1993), Woods et al. (1996), andMatera et al. (1998). Miyata et al. (1998) doubted the acetylcholine role in controlling production of high molecular weight-glycoconjugates in spite of the study by Steel and Hanrahan (1997) on GC of the tracheal epithelium in hamsters.The presence of neutral and acidic sulphated and acidic sialylated glycoconjugates