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Vasopressin receptor 2 stimulation increases permeability in human microvascular endothelial cells (676.16)
Author(s) -
Lopez Ernesto,
Fujiwara Osamu,
Zhu Yong,
Enkhbaatar Perenlei
Publication year - 2014
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.28.1_supplement.676.16
Subject(s) - sepsis , agonist , vasopressin , vasopressin receptor , vascular permeability , medicine , copeptin , receptor , vascular endothelial growth factor , endocrinology , stimulation , chemistry , pharmacology , vegf receptors , antagonist
Arginine vasopressin (AVP) is administered in sepsis to increase arterial pressure by activating AVP receptor 1 (V1R). Limited attention has been given to effects of AVP receptor 2 (V2R) on endothelial cells. Previously, in our ovine model of sepsis, we have reported that treatment of severe sepsis with V1R selective agonist prevents vascular hyper‐permeability as compared to animals treated with non‐selective AVP. We hypothesize that V2R activation is critically involved in the pathogenesis of vascular hyper‐permeability, which is a severe complication of sepsis. Methods: An electrical impedance assay was adapted to assess acute changes of connectivity in confluent Human Lung Microvascular Endothelial Cells (HMVECs). Confluent cells were exposed to different doses of V2R specific agonist, Desmopressin (DDAVP), Vascular Endothelial Growth Factor (VEGF) or vehicle. The intercellular connectivity (electrical impedance) was measured every 15 min during 24 hours (h). A HMVECs permeability assay was also performed measuring the amount of FITC‐dextran passing through the endothelial monolayer after 18 h of treatment with DDAVP or VEGF. Results: V2R expression in HMVECs was verified with RT‐PCR. DDAVP caused a decrease of HMVECs connectivity with a maximum difference at 0.5 h of treatment. Its clear dose dependent effect was also seen at 0.5 h with 0.3nM, 1nM, 3nM (p蠄0.05), 10nM (p蠄0.0001), and 30nM (p蠄0.0001). The effect was similar to changes seen with 3 ng/ml VEGF (p蠄0.0001), but milder than 10 ng/ml VEGF. The changes in HMVECs connectivity remained during the rest of the experiment. The FITC‐dextran permeability assay also showed a trend of increased permeability with 10 nM DDAVP and 50 ng/ml VEGF. Conclusions: These results suggest that the activation of V2R disrupts the endothelial barrier within minutes, thus causing hyper‐permeability. Additional studies are being performed in our in vivo model to elucidate the role of V2R in sepsis induced vascular hyper‐permeability. Grant Funding Source : Supported by NIH RO1 GM097480, SHC85500, SHC84050 and CONACYT‐Mexico