Ih. Sarelius, CELL AND OXYGEN FLOW IN ARTERIOLES CONTROLLING CAPILLARY PERFUSION, The American journal of physiology, 265(5), 1993, pp. 80001682-80001687
Measurements of hemodynamic and oxygen transport characteristics in th
e arterioles that control capillary perfusion in striated muscle were
used to compare oxygen flow into adjacent capillary networks. Observat
ions were made in arterioles arising consecutively (branches 1-3 and t
he last branch) from a single transverse arteriole. During maximal dil
ation [after 5 min of exposure to superfusate with 10(-4) M adenosine
(ADO)], mean cell flow into branches decreased significantly with incr
easing axial distance along the transverse arteriole, from 8.47 +/- 2.
43 x 10(3) (SE) cells/s in branch 1 to 5.56 +/- 2.14 x 10(3) 3.21 +/-
1.30 x 10(3), and 4.00 +/- 1.33 x 10(3) cells/s in successive branches
. During control, cell fluxes were not significantly different by posi
tion (2.21 +/- 1.12, 1.31 +/- 0.42, 0.97 +/- 0.31, and 1.23 +/- 0.40 c
ells/s in branches 1, 2, and 3 and the last branch, respectively). Bra
nch diameters during ADO were not significantly different by position
(26.2 +/- 2.9, 24.5 +/- 1.4, 22.0 +/- 2.8, and 26.7 +/- 2.7 mum, respe
ctively). Hemoglobin saturations during ADO were not different (59.6 /- 2.2, 60.6 +/- 2.3, 60.3 +/- 2.3, and 61.0 +/- 2.3%, respectively),
whereas mean oxygen flow into branch 1 significantly exceeded that int
o branches 2 and 3 and the last branch (1.40 +/- 0.40 vs. 0.60 +/- 0.1
7, 0.53 +/- 0.22, and 0.66 +/- 0.22 pl/min, respectively). During cont
rol, oxygen flows were not significantly different between branches. T
hus, both cell and oxygen flow into these arterioles vary in a systema
tic way dependent on their relative branch position; regulatory proces
ses serve to make oxygen supply more uniform.