PT - JOURNAL ARTICLE AU - JH Calvet AU - F Verra AU - J Maleine AU - MC Millepied AU - A Harf AU - E Escudier TI - Effect of increased pressure on tracheal ciliary beat frequency AID - 10.1034/j.1399-3003.1999.14a14.x DP - 1999 Jul 01 TA - European Respiratory Journal PG - 80--83 VI - 14 IP - 1 4099 - http://erj.ersjournals.com/content/14/1/80.short 4100 - http://erj.ersjournals.com/content/14/1/80.full SO - Eur Respir J1999 Jul 01; 14 AB - Effects of increased ambient pressure on mucociliary clearance have been poorly investigated. The effects of increasing pressures on ciliary beat frequency (CBF) of guinea-pig tracheal rings were studied in vitro. Increased pressures of 25 and 100 kPa induced a significant and equivalent enhancement of CBF from 30 min after the pressure increase. The increase in CBF observed after a pressure increase of 50 kPa (inspiratory oxygen fraction = 21%), was significantly greater than that observed with an equivalent oxygen tension at atmospheric pressure, i.e. with a gas mixture containing 30% oxygen. Addition of N(G)-nitro-L-arginine methylester (L-NAME) inhibited the enhancement in CBF observed after the 25 kPa pressure increase. Addition of L-arginine reversed the effect of L-NAME. These results demonstrate that a pressure increase applied to tracheal rings, in vitro, induces an enhancement of ciliary beat frequency and that generation of nitric oxide may be involved in this ciliary stimulation.