title: Effect of Pseudomonas aeruginosa rhamnolipids on mucociliary transport and ciliary beating.
abstract: Pseudomonas aeruginosa rhamnolipid causes ciliostasis and cell membrane damage to rabbit tissue, is a secretagogue in cats, and inhibits epithelial ion transport in sheep tissue. It could therefore perturb mucociliary clearance. We have investigated the effect of rhamnolipid on mucociliary transport in the anesthetized guinea pig and guinea pig and human respiratory epithelium in vitro. Application of rhamnolipid to the guinea pig tracheal mucosa reduced tracheal mucus velocity (TMV) in vivo in a dose-dependent manner: a 10-microgram bolus caused cessation of TMV without recovery; a 5-micrograms bolus reduced TMV over a period of 2 h by 22.6% (P = 0.037); a 2.5-microgram bolus caused no overall changes in TMV. The ultrastructure of guinea pig tracheal epithelium exposed to 10 micrograms of rhamnolipid in vivo was normal. Application of 1,000 micrograms/ml rhamnolipid had no effect on the ciliary beat frequency (CBF) of guinea pig tracheal rings in vitro after 30 min, but 250 micrograms/ml stopped ciliary beating after 3 h. Treatment with 100 micrograms/ml rhamnolipid caused immediate slowing of the CBF (P less than 0.01) of human nasal brushings (n = 7), which was maintained for 4 h. Mono- and dirhamnolipid had equivalent effects. The CBF of human nasal turbinate organ culture was also slowed by 100 micrograms/ml rhamnolipid, but only after 4 h (CBF test, 9.87 +/- 0.41 Hz; control, 11.48 +/- 0.27 Hz; P less than 0.05, n = 6), and there was subsequent recovery by 14 h.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Thoracic Medicine, National Heart and Lung Institute, London, United Kingdom.
authors.forename: R C
authors.initials: RC
authors.lastname: Read
authors.forename: P
authors.initials: P
authors.lastname: Roberts
authors.forename: N
authors.initials: N
authors.lastname: Munro
authors.forename: A
authors.initials: A
authors.lastname: Rutman
authors.forename: A
authors.initials: A
authors.lastname: Hastie
authors.forename: T
authors.initials: T
authors.lastname: Shryock
authors.forename: R
authors.initials: R
authors.lastname: Hall
authors.forename: W
authors.initials: W
authors.lastname: McDonald-Gibson
authors.forename: V
authors.initials: V
authors.lastname: Lund
authors.forename: G
authors.initials: G
authors.lastname: Taylor
mesh_terms: D000818:Animals; D002923:Cilia / Q000187:drug effects / Q000502:physiology; D006017:Glycolipids / Q000633:toxicity*; D006168:Guinea Pigs; D006801:Humans; D066298:In Vitro Techniques; D009079:Mucociliary Clearance / Q000187:drug effects*; D009297:Nasal Mucosa / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D011552:Pseudomonas Infections / Q000209:etiology; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity*; D012141:Respiratory Tract Infections / Q000209:etiology; D014132:Trachea / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure
chemical_list: D006017:Glycolipids