PMID- 8806904
OWN - NLM
STAT- MEDLINE
DCOM- 19961203
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 80
IP  - 6
DP  - 1996 Jun
TI  - Blood flow distribution in working in situ canine muscle during blood flow 
      reduction.
PG  - 1978-83
AB  - The purpose of this study was to determine whether reduction in apparent muscle 
      O2 diffusing capacity (Dmo2) calculated during reduced blood flow conditions in 
      maximally working muscle is a reflection of alterations in blood flow 
      distribution. Isolated dog gastrocnemius muscle (n = 6) was stimulated for 3 min 
      to achieve peak O2 uptake (VO2) at two levels of blood flow (controlled by pump 
      perfusion): control (C) conditions at normal perfusion pressure (blood flow = 111 
      +/- 10 ml.100 g-1.min-1) and reduced blood flow treatment [ischemia (I); 52 +/- 6 
      ml.100 g-1.min-1]. In addition, maximal vasodilation was achieved by adenosine 
      (A) infusion (10(-2)M) at both levels of blood flow, so that each muscle was 
      subjected randomly to a total of four conditions (C, CA, I, and IA; each 
      separated by 45 min of rest). Muscle blood flow distribution was measured with 
      15-microns-diameter colored microspheres. A numerical integration technique was 
      used to calculate Dmo2 for each treatment with use of a model that calculates O2 
      loss along a capillary on the basis of Fick's law of diffusion. Peak VO2 was 
      reduced significantly (P < 0.01) with ischemia and was unchanged by adenosine 
      infusion at either flow rate (10.6 +/- 0.9, 9.7 +/- 1.0, 6.7 +/- 0.2, and 5.9 +/- 
      0.8 ml.100 g-1.min-1 for C, CA, I, and IA, respectively). Dmo2 was significantly 
      lower by 30-35% (P < 0.01) when flow was reduced (except for CA vs. I; 0.23 +/- 
      0.03, 0.20 +/- 0.02, 0.16 +/- 0.01, and 0.13 +/- 0.01 ml.100 g-1.min-1.Torr-1 for 
      C, CA, I, and IA, respectively). As expressed by the coefficient of variation 
      (0.45 +/- 0.04, 0.47 +/- 0.04, 0.55 +/- 0.03, and 0.53 +/- 0.04 for C, CA, I, and 
      IA, respectively), blood flow heterogeneity per se was not significantly 
      different among the four conditions when examined by analysis of variance. 
      However, there was a strong negative correlation (r = 0.89, P < 0.05) between 
      Dmo2 and blood flow heterogeneity among the four conditions, suggesting that 
      blood flow redistribution (likely a result of a decrease in the number of 
      perfused capillaries) becomes an increasingly important factor in the 
      determination of Dmo2 as blood flow is diminished.
FAU - Kurdak, S S
AU  - Kurdak SS
AD  - Department of Medicine, University of California, San Diego, La Jolla 92093-0623, 
      USA.
FAU - Grassi, B
AU  - Grassi B
FAU - Wagner, P D
AU  - Wagner PD
FAU - Hogan, M C
AU  - Hogan MC
LA  - eng
GR  - AR-40155/AR/NIAMS NIH HHS/United States
GR  - HL-17731/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Animals
MH  - Blood Flow Velocity/*physiology
MH  - Dogs
MH  - Female
MH  - Male
MH  - Muscle, Skeletal/*physiology
MH  - Oxygen/*metabolism
EDAT- 1996/06/01 00:00
MHDA- 1996/06/01 00:01
CRDT- 1996/06/01 00:00
PHST- 1996/06/01 00:00 [pubmed]
PHST- 1996/06/01 00:01 [medline]
PHST- 1996/06/01 00:00 [entrez]
AID - 10.1152/jappl.1996.80.6.1978 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 1996 Jun;80(6):1978-83. doi: 10.1152/jappl.1996.80.6.1978.