Page 1 of 1

The Primary Valves in the Initial Lymphatics during Inflamma

PostPosted: Fri May 25, 2007 1:27 am
by patoco
The Primary Valves in the Initial Lymphatics during Inflammation

Lymphat Res Biol. 2007

Lynch PM, Delano FA, Schmid-Schonbein GW.
Department of Bioengineering, University of California San Diego, La
Jolla, California., Supported by United States Public Health Service
Grant HL 10881.

Background: The primary valve system in the initial lymphatics
prevents fluid transport from the initial lymphatics back into the
interstitium. The authors hypothesize that since the primary valves
are made up of an extraordinarily thin endothelium, they are readily
compromised by mechanical or biochemical inflammatory stimuli. Thus,
the opening dimension of the primary valves and their ability to
prevent reflux into the interstitium during inflammation were

Methods and Results: Acute inflammation was generated in the intact rat spinotrapezius muscle by suffusion of f-Met-Leu-Phe and platelet-
activating factor. Once inflamed, the effective opening dimensions of
the primary valves and the transport back out of the initial
lymphatics were determined by examining the transport of fluorescent
tracers from the interstitium to the lymphatics. Quantum dots and
fluorescently labeled albumin readily enter initial lymphatics from
the interstitium. The maximum diameter of microspheres that enter the
initial lymphatics is between 0.5 mum and 0.8 mum in both control and
inflamed tissue. While under control conditions no quantum dots
escaped from initial lymphatics back into the interstitium, during
inflammation there was extensive escape of quantum dots.

Conclusions: These results suggest that, in acute inflammation, the
function of the endothelial barriers in the initial lymphatics may be
compromised. A failure of the primary lymphatic valves has two

First, fluid clearance from the tissue is less efficient, which causes
the level of edema to increase.

Second, the leaking initial lymphatics allow inflammatory mediators to
accumulate in the tissue, therefore enhancing interstitial and
lymphatic inflammatory reactions.

PMID: 17508898 [PubMed - in process] ... etrieve&...


Pat O'Connor
Lymphedema People