Mucin histochemistry of tracheal goblet cells after oral administration of ambroxol. Acta vet Brno 2001; 70

Abstract 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, rabbit Ambroxol, 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; 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

Involvement of mast cells in monocrotaline-induced pulmonary hypertension in rats

Background: Mast cells (MCs) are implicated in inflammation and tissue remodeling. Accumulation of lung MCs is described in pulmonary hypertension (PH); however, whether MC degranulation and c-kit, a tyrosine kinase receptor critically involved in MC biology, contribute to the pathogenesis and progression of PH has not been fully explored.Methods: Pulmonary MCs of idiopathic pulmonary arterial hypertension (IPAH) patients and monocrotaline-injected rats (MCT-rats) were examined by histochemistry and morphometry. Effects of the specific c-kit inhibitor PLX and MC stabilizer cromolyn sodium salt (CSS) were investigated in MCT-rats both by the preventive and therapeutic approaches. Hemodynamic and right ventricular hypertrophy measurements, pulmonary vascular morphometry and analysis of pulmonary MC localization/counts/activation were performed in animal model studies.Results: There was a prevalence of pulmonary MCs in IPAH patients and MCT-rats as compared to the donors and healthy rats, respectively. Notably, the perivascular MCs were increased and a majority of them were degranulated in lungs of IPAH patients and MCT-rats (p < 0.05 versus donor and control, respectively). In MCT-rats, the pharmacological inhibitions of MC degranulation and c-kit with CSS and PLX, respectively by a preventive approach (treatment from day 1 to 21 of MCT-injection) significantly attenuated right ventricular systolic pressure (RVSP) and right ventricular hypertrophy (RVH). Moreover, vascular remodeling, as evident from the significantly decreased muscularization and medial wall thickness of distal pulmonary vessels, was improved. However, treatments with CSS and PLX by a therapeutic approach (from day 21 to 35 of MCT-injection) neither improved hemodynamics and RVH nor vascular remodeling.Conclusions: The accumulation and activation of perivascular MCs in the lungs are the histopathological features present in clinical (IPAH patients) and experimental (MCT-rats) PH. Moreover, the accumulation and activation of MCs in the lungs contribute to the development of PH in MCT-rats. Our findings reveal an important pathophysiological insight into the role of MCs in the pathogenesis of PH in MCT- rats

Tracheal Epithelium of Rabbits after Repeated Inhalations of Mineral Water Aerosol

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/m2. The altered kinocilia represented 5.8 ± 1.4%. These values were slightly but significantly (α = 0.01) lower compared with controls. A