Teste da sacarina e de palato de rã: ferramentas para estudo do transporte mucociliar

Introdução: Distúrbios no transporte mucociliar (TMC) podem afetar o clearance de secreções, e pode ser medido in vivo, utilizando sacarina, ou in vitro, usando palato de rã. Objetivo: Rever e analisar publicações e resultados sobre TMC com referência sobre teste de sacarina e palato de rã. Métodos: A revisão inclui artigos publicados em periódicos indexados nas bases Medline/Embase, CINAHL e SciELO realizada por três revisores. As palavras-chave utlizadas foram: (mucociliary or mucus) and [(transport or clearance) and (methods and saccharin test/ frog palate)]. Resultados: Foram encontrados 186 artigos, sendo excluídos: 90 pelo título, 41 por resumo, 4 pela língua, 11 não acessíveis, 20 por métodos do TMC incompatíveis com este estudo. Portanto, 20 estudos foram incluídos nesta revisão. Conclusão: Baseando-se nas evidências dos estudos encontrados, observou-se que, na prática clínica, o teste da sacarina mostrou-se mais factível, de baixo custo e boa reprodutibilidade, além promover fácil e rápida análise do TMC.

Luffa Operculata Affects Mucociliary Function of the Isolated Frog Palate

Background Luffa operculata is a medicinal plant used in homeopathic and alternative medicine. In the United States, it is sold in a purified spray form, whereas a homemade L. operculata dry fruit infusion (DFI) is commonly used in Latin America. The L. operculata DFI is applied intranasally, inducing profuse mucous secretion and relieving nasal symptoms. Nevertheless, this medication may cause irritation of the nasal mucosa, as well as epistaxis or anosmia. Given the growing popularity of alternative medicine, a decision was made to evaluate the effects of this substance on mucous membranes. Methods The effects of L. operculata DFI on mucociliary transport velocity, ciliary beat frequency, and transepithelial potential difference (PD) were evaluated in an isolated frog palate preparation. We tested 46 palates immediately before immersion and again at 5 and 20 minutes after immersion. Four groups (n = 10) were tested in frog Ringer: control; L. operculata DFI, 60 mg/L; 600 mg/L; and 1200 mg/L. An additional group was tested using L. operculata DFI prepared with water (600 mg/L of H2O, n = 6). Epithelial samples were harvested for ultrastructural study. Results In treated palates, mucociliary transport velocity and ciliary beat frequency decreased significantly (p < 0.001 and p < 0.008, respectively). There was a dose-dependent decrease in PD modulus (p < .007). Our PD findings indicated ion-fluid transport abnormalities, which were confirmed by transmission electron microscopy that showed enlargement of interepithelial spaces. Conclusion In this ex vivo model, the L. operculata DFI infusion promoted significant changes in the mucociliary function of the epithelium, suggesting that it is potentially noxious to human nasal mucosa.

Mucociliary Transport Function and Damage of Ciliated Epithelium

The influence of epithelial damage on mucociliary transport was studied in relation to the amount of mucus. The mucosal epithelium of mucus-depleted frog palate was dissected and mounted on a plastic plate. Mechanical damages were created on the frog mucosa by pressing a different thickness of boards (2, 3, 5, and 8 mm). Two different amounts of frog mucus (7.9 L [small amount of mucus {S-mucus}]) and 51.0 L [large amount of mucus {L-mucus}])were applied on the frog mucosa with and without mucosal damage. There was no difference in mucociliary transport rate (MTR) on undamaged frog mucosa between S-mucus and L-mucus. However, on the damaged mucosa, MTR of S-mucus was significantly decreased compared with that of L-mucus. Moreover, capability of mucus transportation across the mucosal damage was significantly lower in S-mucus than in L-mucus. Results indicate that the larger the mucus amount becomes, the more the mucus travels the damaged epithelium. Moreover, MTR of L-mucus was decreased with increasing the degree of epithelial damage. This study indicates that the degree of loss of cilia is an important factor of mucociliary deceleration. (American Journal of Rhinology 16, 215–219, 2002)