Nasal mucus clearance in rats: Differences with sex and phase of the oestrous cycle

Autor: Aracy Pereira Silveira Balbani, G. Lorenzi, Milton A. Martins, M. Macchione, E T Guimaraes, Paulo Hilário Nascimento Saldiva, Paulo S. O. Paiva, Malcolm King, Gregório Santiago Montes, M A C Parada
Rok vydání: 1995
Předmět:
Zdroj: Journal of Applied Toxicology. 15:289-295
ISSN: 1099-1263
0260-437X
DOI: 10.1002/jat.2550150410
Popis: We studied the changes in airway mucus rheology and clearability, as well as in morphometric indices, between male rats and females in either the oestrous or dioestrous phases of the oestrous cycle. Three-month-old Wistar rats were studied and the phases of the oestrous cycle were determined based on analysis of vaginal smears stained by a modified Shorr's procedure. Nasal mucus samples were analysed by means of magnetic rheometry and determination of in vitro transport rate in the frog palate preparation. In situ clearance on the exposed nasal septum was also determined. The mucociliary velocity in situ was significantly affected by both sex and the oestrous cycle phase. In female rats, dioestrous phase clearance was significantly slower than the oestrous phase one. Clearance in male rats was faster than that of both the phases studied in females. Mucus rigidity of females in the oestrous phase was more rigid than that of females in the dioestrous phase and that of males. Mucus viscosity/elasticity ratio for deformations performed at high frequencies was greater for females in comparison with males. Cough clearability computed on the basis of rheological parameters was predicted to be more favourable in females. There were no significant differences between the three groups in mucociliary clearance in vitro. Morphometric studies of the nasal epithelium showed that epithelial and glandular volumes did not exhibit sex- or oestrous-phase-related differences, but the amount of epithelial acidic glycoproteins was lower in females in the oestrous phase in comparison with males and those in the dioestrous phase, the same trend being observed in the glands of the lamina propria. The finding of significant differences of mucus rheology and mucus airway histochemistry may be important in explaining differences between sexes in the susceptibility to the effects of airborne noxious stimulants, as suggested by some epidemiological data.
Databáze: OpenAIRE
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