| First Author | VanTeeffelen JW | Year | 2008 |
| Journal | J Physiol | Volume | 586 |
| Issue | 13 | Pages | 3207-18 |
| PubMed ID | 18450777 | Mgi Jnum | J:176396 |
| Mgi Id | MGI:5291575 | Doi | 10.1113/jphysiol.2008.152975 |
| Citation | VanTeeffelen JW, et al. (2008) Bradykinin- and sodium nitroprusside-induced increases in capillary tube haematocrit in mouse cremaster muscle are associated with impaired glycocalyx barrier properties. J Physiol 586(13):3207-18 |
| abstractText | Previous studies have suggested that agonists may increase functionally perfused capillary volume by modulation of blood-excluding glycocalyx volume, but direct evidence for this association is lacking at the moment. Using intravital microscopic visualization of mouse cremaster muscle, we determined the effects of bradykinin (10(-5) M) and sodium nitroprusside (10(-6) M) on capillary tube haematocrit and glycocalyx barrier properties. In control C57Bl/6 mice (n = 10), tube haematocrit in capillaries (n = 71) increased (P < 0.05) from 8.7 +/- 0.3% during baseline to 21.2 +/- 1.2 and 22.2 +/- 0.9% during superfusion with bradykinin and nitroprusside, respectively. In parallel, the exclusion zone of FITC-labelled 70 kDa dextrans decreased (P < 0.05) from 0.37 +/- 0.01 microm during baseline to 0.17 +/- 0.01 microm with bradykinin and 0.15 +/- 0.01 microm with nitroprusside. Bradykinin and nitroprusside had no effect on dextran exclusion and tube haematocrit in capillaries (n = 55) of hyperlipidemic ApoE3-Leiden mice, which showed impaired exclusion of 70 kDa dextrans (0.05 +/- 0.02 microm; P < 0.05 versus C57Bl/6) and increased capillary tube haematocrit (23 +/- 0.8%; P < 0.05 versus C57Bl/6) under baseline conditions, indicating glycocalyx degradation. Our data show that vasodilator substances increase functionally perfused capillary volume and that this effect is associated with a reduction in glycocalyx exclusion of 70 kDa dextrans. Modulation of glycocalyx volume might represent a novel mechanism of perfusion control at the capillary level. |
