title: Transmural pressure during cardiogenic oscillations in rodent diaphragmatic lymphatic vessels.
abstract: BACKGROUND
  The mechanism of initial lymphatic filling and the role of cardiogenic tissue motion in promoting lymph formation and propulsion are at present still controversial issues, in particular when considering interstitial tissues whose fluid pressure is well below atmospheric. To elucidate these aspects, the micropuncture technique was used to record interstitial (P(int)) and intralymphatic pressure (P(lymph)) simultaneously in the diaphragmatic lymphatic plexus draining the pleural cavity.
  
  
  RESULTS
  The diaphragmatic lymphatic network was identified in anesthetized rabbits and rats through fluorescent dextrans injected intrapleurally. All P(lymph) and P(int) traces were pulsatile, oscillating either in-phase (33% of traces) or out-of-phase (67%) during cardiogenic swings. P(lymph) swept between -4.1 +/- 0.9 (SE) mmHg and 3.5 +/- 1.1 mmHg in rabbits, and between -5.1 +/- 1.0 mmHg and -2.7 +/- 1.1 mmHg in rats. P(int) oscillated between -0.8 +/- 0.7 mmHg and 4.9 +/- 0.7 mmHg in rabbits, and between -0.6 +/- 0.8 mmHg and 0.9 +/- 0.7 mmHg in rats.
  
  
  CONCLUSIONS
  The data revealed a great functional complexity of the diaphragmatic lymphatic network and suggested that cardiogenic oscillations may play an important role in promoting lymph formation and propulsion from interstitial tissues with subatmospheric tissue pressure.
authors.affiliation: Dipartimento di Scienze Biomediche Sperimentali e Cliniche, Università degli Studi dell'Insubria, Varese, Italy. Daniela.Negrini@uninsubria.it
authors.forename: Daniela
authors.initials: D
authors.lastname: Negrini
authors.forename: Andrea
authors.initials: A
authors.lastname: Moriondo
authors.forename: Sylvain
authors.initials: S
authors.lastname: Mukenge
mesh_terms: D000818:Animals; D003911:Dextrans; D003964:Diaphragm / Q000502:physiology*; D005260:Female; D005456:Fluorescent Dyes; D006321:Heart / Q000502:physiology*; D042601:Lymphatic Vessels / Q000502:physiology*; D008297:Male; D011817:Rabbits; D051381:Rats
chemical_list: D003911:Dextrans; D005456:Fluorescent Dyes