Ciliary Ultrastructure and Beating Activity in Rat and Guinea‐pig Respiratory Mucosa

Abstract

1. The rat and the guinea-pig are commonly used animals when the effects of drugs on ciliary activity in respiratory airways are studied. There are few data concerning the possible differences in ciliary function between these two animals. 2. Using a photodetector method we measured the ciliary beating frequency (CBF) from the upper part of the trachea, the lower part of the trachea and the distal part of the main bronchi (subsegmental bronchi) of rat and guinea-pig respiratory tract. In addition, the structure of the cilia was studied using scanning electron microscopy (SEM). 3. CBF in the rat respiratory tract was significantly lower than in the guinea-pigs. In the upper trachea, the CBF for rat was 12.7 beats/s and 15.3 beats/s for guinea-pig. The respective values were 9.2/16.0 beats/s in the lower part of the trachea and 6.9/13.8 beats/s in subsegmental bronchi. In both rats and guinea-pigs CBF was lower in the subsegmental bronchi than in the trachea (rat: 25.0-45.7%, guinea-pig: 9.8-13.8%). 4. In addition to higher CBF, the quality of the photo-electrical signal was better from guinea-pig tissues, probably as a result of the larger amounts of ciliated cells and longer cilia of guinea-pig respiratory epithelial compared to those in rat mucosa. 5. SEM showed that the rat cilia were on average shorter (3.6 vs 4.3 microns) and thinner (0.19 vs 0.22 microns) than those of the guinea-pig. Rat mucosa was markedly less ciliated than the respiratory mucosa of the guinea-pig.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of different mechanical ventilation strategies on the mucociliary system

“…Other factors, such as gravity, airway geometry, fluid rheological properties and quantities, as well as regional lung mechanics (local airway resistance and compliance) interact to influence the net movement of secretions [4]. Because the mucociliary system represents an important part of the respiratory defenses [5], the potential influence of MV on the tracheal epithelia and mucociliary system deserves close consideration. The mucociliary functions depend on the integration of ciliated epithelium, periciliary fluid, and mucus [6] and may be disturbed by several factors, such as increased mucus production, abnormal mucus rheology, abnormal ciliary activity, or loss of ciliated cells [7,8].…”

Avaliação morfo-funcional do sistema mucociliar de traquéia de rato submetida a diferentes métodos de preservação em modelo de isquemia experimental

“…É a hidrólise do ATP pela dineína que promove o batimento ciliar, no sentido proximal, sincrônico, numa freqüência de 10 a 20 Hz (Sleigh et al, 1988). A depender da localização da célula ciliada na via aérea e da espécie do animal utilizado na avaliação, a quantidade de cílios por célula, o comprimento dos cílios e a freqüência de batimento ciliar podem variar (Joki et al, 1995).…”