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Capillary filtration coefficient is independent of number of perfused capillaries in cat skeletal muscle

Bentzer, Peter LU ; Kongstad, Lis LU and Grände, Per-Olof LU (2001) In American Journal of Physiology: Heart and Circulatory Physiology 280(6). p.2697-2706
Abstract
The capillary filtration coefficient (CFC) is assumed to reflect both microvascular hydraulic conductivity and the number of perfused capillaries at a given moment (precapillary sphincter activity). Estimation of hydraulic conductivity in vivo with the CFC method has therefore been performed under conditions of unchanged vascular tone and metabolic influence. There are studies, however, that did not show any change in CFC after changes in vascular tone and metabolic influence, and these studies indicate that CFC may not be influenced by alteration in the number of perfused capillaries. The present study reexamined to what extent CFC in a pressure-controlled preparation depends on the vascular tone and number of perfused capillaries by... (More)
The capillary filtration coefficient (CFC) is assumed to reflect both microvascular hydraulic conductivity and the number of perfused capillaries at a given moment (precapillary sphincter activity). Estimation of hydraulic conductivity in vivo with the CFC method has therefore been performed under conditions of unchanged vascular tone and metabolic influence. There are studies, however, that did not show any change in CFC after changes in vascular tone and metabolic influence, and these studies indicate that CFC may not be influenced by alteration in the number of perfused capillaries. The present study reexamined to what extent CFC in a pressure-controlled preparation depends on the vascular tone and number of perfused capillaries by analyzing how CFC is influenced by 1) vasoconstriction, 2) increase in metabolic influence by decrease in arterial blood pressure, and 3) occlusion of precapillary microvessels by arterial infusion of microspheres. CFC was calculated from the filtration rate induced by a fixed decrease in tissue pressure. Vascular tone was increased in two steps by norepinephrine (n = 7) or angiotensin II (n = 6), causing a blood flow reduction from 7.2 +/- 0.8 to at most 2.7 +/- 0.2 ml . min(-1) . 100 g(-1) (P< 0.05). The decrease in arterial pressure reduced blood flow from 4.8 +/- 0.4 to 1.40 +/- 0.1 ml . min(-1) . 100 g(-1) (n = 6). Vascular resistance increased to 990 +/- 260% of control after the infusion of microspheres (n = 6). CFC was not significantly altered from control after any of the experimental interventions. We conclude that CFC under these conditions is independent of the vascular tone and number of perfused capillaries and that variation in CFC reflects variation in microvascular hydraulic conductivity. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
American Journal of Physiology: Heart and Circulatory Physiology
volume
280
issue
6
pages
2697 - 2706
publisher
American Physiological Society
external identifiers
  • wos:000168761600035
  • scopus:0034985018
ISSN
1522-1539
language
English
LU publication?
yes
id
cdfa22db-9c30-44d3-95e0-6850247d0d50 (old id 1119235)
alternative location
http://ajpheart.physiology.org/cgi/content/full/280/6/H2697
date added to LUP
2008-06-24 13:58:18
date last changed
2018-01-07 05:20:14
@article{cdfa22db-9c30-44d3-95e0-6850247d0d50,
  abstract     = {The capillary filtration coefficient (CFC) is assumed to reflect both microvascular hydraulic conductivity and the number of perfused capillaries at a given moment (precapillary sphincter activity). Estimation of hydraulic conductivity in vivo with the CFC method has therefore been performed under conditions of unchanged vascular tone and metabolic influence. There are studies, however, that did not show any change in CFC after changes in vascular tone and metabolic influence, and these studies indicate that CFC may not be influenced by alteration in the number of perfused capillaries. The present study reexamined to what extent CFC in a pressure-controlled preparation depends on the vascular tone and number of perfused capillaries by analyzing how CFC is influenced by 1) vasoconstriction, 2) increase in metabolic influence by decrease in arterial blood pressure, and 3) occlusion of precapillary microvessels by arterial infusion of microspheres. CFC was calculated from the filtration rate induced by a fixed decrease in tissue pressure. Vascular tone was increased in two steps by norepinephrine (n = 7) or angiotensin II (n = 6), causing a blood flow reduction from 7.2 +/- 0.8 to at most 2.7 +/- 0.2 ml . min(-1) . 100 g(-1) (P&lt; 0.05). The decrease in arterial pressure reduced blood flow from 4.8 +/- 0.4 to 1.40 +/- 0.1 ml . min(-1) . 100 g(-1) (n = 6). Vascular resistance increased to 990 +/- 260% of control after the infusion of microspheres (n = 6). CFC was not significantly altered from control after any of the experimental interventions. We conclude that CFC under these conditions is independent of the vascular tone and number of perfused capillaries and that variation in CFC reflects variation in microvascular hydraulic conductivity.},
  author       = {Bentzer, Peter and Kongstad, Lis and Grände, Per-Olof},
  issn         = {1522-1539},
  language     = {eng},
  number       = {6},
  pages        = {2697--2706},
  publisher    = {American Physiological Society},
  series       = {American Journal of Physiology: Heart and Circulatory Physiology},
  title        = {Capillary filtration coefficient is independent of number of perfused capillaries in cat skeletal muscle},
  volume       = {280},
  year         = {2001},
}