### Abstract

The objective of this study was to quantify the heterogeneity of topological, morphological, and hemodynamic parameters in microvascular networks and to identify functionally relevant correlations among these parameters. Seven networks in the rat mesentery (383913 vessel segments per network) were examined, and measurements were made of segment generation, diameter, length, and hematocrit in all segments (n = 3,129) and of flow velocity (only in 3 networks, 1,321 segments). In addition, hematocrit, flow rate, and pressure were derived for all segments from a mathematical simulation. All parameters obtained exhibit heterogeneous distributions with coefficients of variation ranging from 0.28 (capillary diameter) to > 1.5 (volume flow and pressure gradient). Several strong correlations exist between parameters, e.g., discharge hematocrit increases with vessel diameter, and shear rate increases with intravascular pressure. Because of such correlations, the extrapolation from average values for 'typical vessels' to network properties can lead to substantial errors. For example, the mean network transit time estimated based on averaged quantities is 6.5 s, which is about 60% higher than the true value (4.08 s). Simplified models of the vascular bed may therefore be inadequate to describe functional properties of the microcirculation.

Original language | English (US) |
---|---|

Journal | American Journal of Physiology - Heart and Circulatory Physiology |

Volume | 269 |

Issue number | 5 38-5 |

State | Published - 1995 |

Externally published | Yes |

### Fingerprint

### Keywords

- hematocrit
- pressure
- shear rate
- topology
- volume flow

### ASJC Scopus subject areas

- Physiology

### Cite this

*American Journal of Physiology - Heart and Circulatory Physiology*,

*269*(5 38-5).

**Structure and hemodynamics of microvascular networks : Heterogeneity and correlations.** / Pries, A. R.; Secomb, Timothy W; Gaehtgens, P.

Research output: Contribution to journal › Article

*American Journal of Physiology - Heart and Circulatory Physiology*, vol. 269, no. 5 38-5.

}

TY - JOUR

T1 - Structure and hemodynamics of microvascular networks

T2 - Heterogeneity and correlations

AU - Pries, A. R.

AU - Secomb, Timothy W

AU - Gaehtgens, P.

PY - 1995

Y1 - 1995

N2 - The objective of this study was to quantify the heterogeneity of topological, morphological, and hemodynamic parameters in microvascular networks and to identify functionally relevant correlations among these parameters. Seven networks in the rat mesentery (383913 vessel segments per network) were examined, and measurements were made of segment generation, diameter, length, and hematocrit in all segments (n = 3,129) and of flow velocity (only in 3 networks, 1,321 segments). In addition, hematocrit, flow rate, and pressure were derived for all segments from a mathematical simulation. All parameters obtained exhibit heterogeneous distributions with coefficients of variation ranging from 0.28 (capillary diameter) to > 1.5 (volume flow and pressure gradient). Several strong correlations exist between parameters, e.g., discharge hematocrit increases with vessel diameter, and shear rate increases with intravascular pressure. Because of such correlations, the extrapolation from average values for 'typical vessels' to network properties can lead to substantial errors. For example, the mean network transit time estimated based on averaged quantities is 6.5 s, which is about 60% higher than the true value (4.08 s). Simplified models of the vascular bed may therefore be inadequate to describe functional properties of the microcirculation.

AB - The objective of this study was to quantify the heterogeneity of topological, morphological, and hemodynamic parameters in microvascular networks and to identify functionally relevant correlations among these parameters. Seven networks in the rat mesentery (383913 vessel segments per network) were examined, and measurements were made of segment generation, diameter, length, and hematocrit in all segments (n = 3,129) and of flow velocity (only in 3 networks, 1,321 segments). In addition, hematocrit, flow rate, and pressure were derived for all segments from a mathematical simulation. All parameters obtained exhibit heterogeneous distributions with coefficients of variation ranging from 0.28 (capillary diameter) to > 1.5 (volume flow and pressure gradient). Several strong correlations exist between parameters, e.g., discharge hematocrit increases with vessel diameter, and shear rate increases with intravascular pressure. Because of such correlations, the extrapolation from average values for 'typical vessels' to network properties can lead to substantial errors. For example, the mean network transit time estimated based on averaged quantities is 6.5 s, which is about 60% higher than the true value (4.08 s). Simplified models of the vascular bed may therefore be inadequate to describe functional properties of the microcirculation.

KW - hematocrit

KW - pressure

KW - shear rate

KW - topology

KW - volume flow

UR - http://www.scopus.com/inward/record.url?scp=0028875845&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028875845&partnerID=8YFLogxK

M3 - Article

C2 - 7503269

AN - SCOPUS:0028875845

VL - 269

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6143

IS - 5 38-5

ER -