Cargando…

Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics

The mechanisms that control phasic and tonic contractions of lymphatic vessels are poorly understood. We hypothesized that rho kinase ROCK, previously shown to increase calcium (Ca(2+)) sensitivity in vascular smooth muscle, enhances lymphatic contractile activity in a similar fashion. Contractions...

Descripción completa

Detalles Bibliográficos
Autores principales: Kurtz, Kristine H., Souza-Smith, Flavia M., Moor, Andrea N., Breslin, Jerome W.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978029/
https://www.ncbi.nlm.nih.gov/pubmed/24710574
http://dx.doi.org/10.1371/journal.pone.0094082
_version_ 1782310499375906816
author Kurtz, Kristine H.
Souza-Smith, Flavia M.
Moor, Andrea N.
Breslin, Jerome W.
author_facet Kurtz, Kristine H.
Souza-Smith, Flavia M.
Moor, Andrea N.
Breslin, Jerome W.
author_sort Kurtz, Kristine H.
collection PubMed
description The mechanisms that control phasic and tonic contractions of lymphatic vessels are poorly understood. We hypothesized that rho kinase ROCK, previously shown to increase calcium (Ca(2+)) sensitivity in vascular smooth muscle, enhances lymphatic contractile activity in a similar fashion. Contractions of isolated rat mesenteric lymphatic vessels were observed at a luminal pressure of 2 cm H(2)O in a 37°C bath. The expression of ROCK in isolated rat mesenteric lymphatic vessels was assessed by Western blotting and confocal microscopy. The role of ROCK in contractile function was tested using two specific yet structurally distinct inhibitors: H1152 (0.1–10 μM) and Y-27632 (0.5–50 μM). In addition, lymphatics were transfected with constitutively active (ca)-ROCK protein (2 μg/ml) to assess gain of contractile function. Vessel diameter and the concentration of intracellular free Ca(2+) ([Ca(2+)](i)) were simultaneously measured in a subset of isolated lymphatics loaded with the Ca(2+)-sensing dye fura-2. The results show expression of both the ROCK1 and ROCK2 isoforms in lymphatic vessels. Inhibition of ROCK increased lymphatic end diastolic diameter and end systolic diameter in a concentration-dependent manner. Significant reductions in lymphatic tone and contraction amplitude were observed after treatment 1–10 μM H1152 or 25–50 μM Y-27632. H1152 (10 μM) also significantly reduced contraction frequency. Transient increases in [Ca(2+)](i) preceded each phasic contraction, however this pattern was disrupted by either 10 μM H1152 or 50 μM Y-27632 in the majority of lymphatics studied. The significant decrease in tone caused by H1152 or Y-27632 was not associated with a significant change in the basal [Ca(2+)](i) between transients. Transfection with ca-ROCK protein enhanced lymphatic tone, but was not associated with a significant change in basal [Ca(2+)](i). Our data suggest that ROCK mediates normal tonic constriction and influences phasic contractions in lymphatics. We propose that ROCK modulates Ca(2+) sensitivity of contractile proteins in lymphatics.
format Online
Article
Text
id pubmed-3978029
institution National Center for Biotechnology Information
language English
publishDate 2014
publisher Public Library of Science
record_format MEDLINE/PubMed
spelling pubmed-39780292014-04-11 Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics Kurtz, Kristine H. Souza-Smith, Flavia M. Moor, Andrea N. Breslin, Jerome W. PLoS One Research Article The mechanisms that control phasic and tonic contractions of lymphatic vessels are poorly understood. We hypothesized that rho kinase ROCK, previously shown to increase calcium (Ca(2+)) sensitivity in vascular smooth muscle, enhances lymphatic contractile activity in a similar fashion. Contractions of isolated rat mesenteric lymphatic vessels were observed at a luminal pressure of 2 cm H(2)O in a 37°C bath. The expression of ROCK in isolated rat mesenteric lymphatic vessels was assessed by Western blotting and confocal microscopy. The role of ROCK in contractile function was tested using two specific yet structurally distinct inhibitors: H1152 (0.1–10 μM) and Y-27632 (0.5–50 μM). In addition, lymphatics were transfected with constitutively active (ca)-ROCK protein (2 μg/ml) to assess gain of contractile function. Vessel diameter and the concentration of intracellular free Ca(2+) ([Ca(2+)](i)) were simultaneously measured in a subset of isolated lymphatics loaded with the Ca(2+)-sensing dye fura-2. The results show expression of both the ROCK1 and ROCK2 isoforms in lymphatic vessels. Inhibition of ROCK increased lymphatic end diastolic diameter and end systolic diameter in a concentration-dependent manner. Significant reductions in lymphatic tone and contraction amplitude were observed after treatment 1–10 μM H1152 or 25–50 μM Y-27632. H1152 (10 μM) also significantly reduced contraction frequency. Transient increases in [Ca(2+)](i) preceded each phasic contraction, however this pattern was disrupted by either 10 μM H1152 or 50 μM Y-27632 in the majority of lymphatics studied. The significant decrease in tone caused by H1152 or Y-27632 was not associated with a significant change in the basal [Ca(2+)](i) between transients. Transfection with ca-ROCK protein enhanced lymphatic tone, but was not associated with a significant change in basal [Ca(2+)](i). Our data suggest that ROCK mediates normal tonic constriction and influences phasic contractions in lymphatics. We propose that ROCK modulates Ca(2+) sensitivity of contractile proteins in lymphatics. Public Library of Science 2014-04-07 /pmc/articles/PMC3978029/ /pubmed/24710574 http://dx.doi.org/10.1371/journal.pone.0094082 Text en © 2014 Kurtz et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Kurtz, Kristine H.
Souza-Smith, Flavia M.
Moor, Andrea N.
Breslin, Jerome W.
Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics
title Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics
title_full Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics
title_fullStr Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics
title_full_unstemmed Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics
title_short Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics
title_sort rho kinase enhances contractions of rat mesenteric collecting lymphatics
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978029/
https://www.ncbi.nlm.nih.gov/pubmed/24710574
http://dx.doi.org/10.1371/journal.pone.0094082
work_keys_str_mv AT kurtzkristineh rhokinaseenhancescontractionsofratmesentericcollectinglymphatics
AT souzasmithflaviam rhokinaseenhancescontractionsofratmesentericcollectinglymphatics
AT moorandrean rhokinaseenhancescontractionsofratmesentericcollectinglymphatics
AT breslinjeromew rhokinaseenhancescontractionsofratmesentericcollectinglymphatics