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Transmural flow modulates the lymphatic myogenic response in bovine mesenteric lymphatic vessels
Author(s) -
Venugopal Arun M,
Quick Christopher M,
Laine Glen A,
Stewart Randolph H
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a493-d
Subject(s) - lymphatic system , anatomy , lymph , oncotic pressure , lymphatic vessel , contraction (grammar) , medicine , contractility , cardiology , chemistry , pathology , albumin , cancer , metastasis
Lymphatic vessels actively propel lymph through unidirectional valves via intrinsic cyclic contractions of lymphatic smooth muscle. The frequency and strength of this contractile activity is modulated by endothelial shear stress and transmural pressure. The effect of transmural pressure has classically been attributed to alterations in hoop stress; however, lymphatic vessels may respond to changes in transmural flow governed by Starling forces. To test this hypothesis, isolated valveless segments of post‐nodal bovine mesenteric lymphatic vessels were subjected to two transmural oncotic pressure gradients. Vessels were cannulated in a tubular organ bath at 37°C and perfused with APSS (1% albumin in physiological salt solution). A video dimension analyzer and pressure transducer were used to simultaneously record instantaneous diameter and pressure. Contraction frequency, end‐diastolic diameter (EDD), end‐systolic diameter (ESD) and stroke area {π (EDD2‐ESD2)/4} were determined at four transmural pressures, with and without addition of 1% dextran‐70 to the perfusate. Dextran‐70 increased ESD and decreased stroke area, suggesting that transmural flow stimulates lymphatic contractile activity. This preliminary study suggests that transmural flow has a role in regulating lymphatic pump function.