title: Release of mucus glycoconjugates by Pseudomonas aeruginosa rhamnolipid into feline trachea in vivo and human bronchus in vitro.
abstract: Pseudomonas aeruginosa colonizes the lower respiratory tracts of patients with severe bronchiectasis, including cystic fibrosis, a condition associated with increased airway mucus output. We have shown that an extract containing chloroform-soluble extracellular products of P. aeruginosa releases glycoconjugates into the cat trachea in vivo. This activity was not related to pyocyanin, a major component of the extract, but was associated with the rhamnolipids. Purified monorhamnolipid (100 micrograms/ml) released radiolabeled and periodic acid-Schiff (PAS)-reactive glycoconjugates (delta 3H = +490 +/- 70%, delta 35S = +170 +/- 40%, delta PAS = +8.6 +/- 1.7 micrograms/min; n = 6, P less than 0.02 for each). Dirhamnolipid (200 micrograms/ml) was also effective (delta 3H = +640 +/- 70%, delta 35S = +130 +/- 20%, delta PAS = +9.3 +/- 1.5 micrograms/min; n = 6, P less than 0.02 for each). Monorhamnolipid (100 micrograms/ml) also released 35S-labeled and PAS-reactive glycoconjugates from human bronchial tissue in vitro (delta 35S = +189 +/- 47%, delta PAS = +26.3 +/- 8.5 micrograms/min; n = 7, P less than 0.001 versus control tissues in which no stimulus was given). The cat tracheal glycoconjugates released by the rhamnolipids differed from those released by pilocarpine 50 microM, in having a higher 3H:35S ratio (P less than 0.001). After gel chromatography on a Sepharose CL-4B column, the void volume fractions of the glycoconjugates also had different profiles in a cesium chloride density gradient. Those released by rhamnolipid banded at 1.62 g/ml, while those released by pilocarpine banded mainly at 1.50 g/ml, with some of the higher density material also present.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology, St. George's Hospital Medical School, London, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Somerville
authors.forename: G W
authors.initials: GW
authors.lastname: Taylor
authors.forename: D
authors.initials: D
authors.lastname: Watson
authors.forename: N B
authors.initials: NB
authors.lastname: Rendell
authors.forename: A
authors.initials: A
authors.lastname: Rutman
authors.forename: H
authors.initials: H
authors.lastname: Todd
authors.forename: J R
authors.initials: JR
authors.lastname: Davies
authors.forename: R
authors.initials: R
authors.lastname: Wilson
authors.forename: P
authors.initials: P
authors.lastname: Cole
authors.forename: P S
authors.initials: PS
authors.lastname: Richardson
mesh_terms: D000818:Animals; D001980:Bronchi / Q000378:metabolism*; D002415:Cats; D006017:Glycolipids / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D009093:Mucus / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology; D010619:Phenazines / Q000494:pharmacology; D010860:Pigments, Biological / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D014132:Trachea / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology
chemical_list: D006017:Glycolipids; D010619:Phenazines; D010860:Pigments, Biological