Effects of Type II diabetes on muscle microvascular oxygen pressures.
We tested the hypothesis that muscle microvascular O2 pressure (PmvO2; reflecting the O2 delivery (QO2) to O2 uptake (VO2) ratio) would be lowered in the spinotrapezius muscle of Goto-Kakizaki (GK) Type II diabetic rats (n=7) at rest and during twitch contractions when compared to control (CON; n=5) rats. At rest, PmvO2 was lower in GK versus CON rats (CON: 29+/-2; GK: 18+/-2Torr; P<0.05). At the onset of contractions, GK rats evidenced a faster change in PmvO2 than CON (i.e., time constant (tau); CON: 16+/-4; GK: 6+/-2s; P<0.05). In contrast to the monoexponential fall in PmvO2 to the steady-state level seen in CON, GK rats exhibited a biphasic PmvO2 response that included a blunted (or non-existent) PmvO2 decrease followed by recovery to a steady-state PmvO2 that was at, or slightly above, resting values. Compared with CON, this decreased PmvO2 across the transition to a higher metabolic rate in Type II diabetes would be expected to impair blood-muscle O2 exchange and contractile function.
Padilla
Danielle J
DJ
Department of Anatomy and Physiology, 228 Coles Hall, Kansas State University, Manhattan, KS 66506, United States.
McDonough
Paul
P
Behnke
Brad J
BJ
Kano
Yutaka
Y
Hageman
K Sue
KS
Musch
Timothy I
TI
Poole
David C
DC
D000704:Analysis of Variance; D000818:Animals; D002196:Capillaries / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004195:Disease Models, Animal; D018149:Glucose Intolerance / Q000097:blood*; D008297:Male; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D018709:Statistics, Nonparametric
D010100:Oxygen