Ultrastructural and ultracytochemical study of the human nasal respiratory epithelium in vasomotor rhinitis.

OBJECTIVES: Several pieces of evidence have suggested that nitric oxide (NO) fulfills important functions in the respiratory mucosa, under both normal and pathological conditions. This study was performed to investigate the role of NO in the nasal respiratory epithelium of patients affected by vasomotor rhinitis. The structure and ultrastructure of the epithelium were also examined. MATERIAL AND METHODS: The localization of NO synthase activity was determined by means of reduced nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase ultracytochemistry. Nasal mucosa was obtained from patients who had undergone surgical therapy for reduction of the inferior turbinate. RESULTS: Examination of hematoxylin-eosin-stained sections revealed that most of the nasal mucosa covering the surgical samples was characterized by severe epithelial damage. The ultrastructural study confirmed the light microscopic observations. Ciliary loss, absence of the intercellular junctions and distension of the intercellular spaces were found in the damaged epithelium. The basement membrane was frequently interrupted. Some epithelial cells were identified as basal cells. Other cells of the damaged epithelium were probably involuted ciliated and goblet cells. The ultracytochemical study showed that the basal cells were NADPH-diaphorase-negative in healthy subjects and strongly NADPH-diaphorase-positive in subjects with vasomotor rhinitis. CONCLUSIONS: It is suggested that NO has cytotoxic effects and causes inhibition of mitotic activity in the basal cells, leading to epithelial disruption and breakdown of the protective functions of the epithelium.

Ultracytochemical localization of the NADPH-d activity in the human nasal respiratory mucosa in vasomotor rhinitis.

OBJECTIVES: Description of the ultrastructural localization of nitric oxide synthase in the blood vessels of the nasal respiratory mucosa in patients with vasomotor rhinitis. STUDY DESIGN: This research was conducted on seven patients--men and women, ages 20 to 45 years--suffering from vasomotor rhinitis and who had undergone surgical therapy for reduction of the inferior turbinates. METHODS: To study the ultrastructural localization of nitric oxide synthase, NADPH-diaphorase cytochemistry was employed. Samples of the nasal mucosa were obtained from inferior turbinates. RESULTS: The endothelial cells of the arterioles, capillaries, venules and cavernous sinuses revealed a distribution of the enzymatic activity similar to that found in unaffected subjects. A strong enzymatic activity was recognized in the smooth muscle cells of the cavernous sinuses. The smooth muscle cells of arterioles and venules were generally found to be negative to enzymatic reaction. CONCLUSIONS: This study suggests that the vascular disorders of the vasomotor rhinitis depend, at least in part, from nitric oxide synthase induction in the smooth muscle cells of the cavernous sinuses.

[Clinical and morphofunctional changes in the mucosa of the inferior nasal conchae in various forms of chronic rhinitis]. / Klinicheskie i morfofunktsional'nye izmeneniia slizistoi obolochki nizhnikh nosovykh rakovin pri nekotorykh formakh khronicheskogo rinita.

Having in view the concept about a close relationship between morphofunctional changes and clinical picture of the disease, 35 patients of different sex, age and various duration of the disease were examined, in order to clarify certain modifications of chronic rhinitis and mechanisms of its pathogenesis. It was found that the forms of the disease were characterized by structural changes of the mucosa, whose microrhinoscopic picture was very different in the case of hyperplastic rhinitis. Changes in hydrolytic enzymes were dissimilar in the case of various clinical forms of the disease. Most demonstrative were the changes in alkaline phosphatase and ATPase in the glandular epithelium and walls of blood vessels in the mucosa. This can be used as an indirect sign of the functional state of the mucosa. Significant enzymatic changes reflect metabolic shifts in mucous structural components and can serve as the basis for the development of hypertrophic and hyperplastic processes.