Dynamics of microvascular oxygen pressure during rest-contraction transition in skeletal muscle of diabetic rats.
Am J Physiol Heart Circ Physiol
; 283(3): H926-32, 2002 Sep.
Article
en En
| MEDLINE
| ID: mdl-12181120
ABSTRACT
Type I diabetes reduces dramatically the capacity of skeletal muscle to receive oxygen (QO(2)). In control (C; n = 6) and streptozotocin-induced diabetic (D n = 6, plasma glucose = 25.3 +/- 3.9 mmol/l and C 8.3 +/- 0.5 mmol/l) rats, phosphorescence quenching was used to test the hypothesis that, in D rats, the decline in microvascular PO(2) [Pm(O(2)), which reflects the dynamic balance between O(2) utilization (VO(2)) and QO(2)] of the spinotrapezius muscle after the onset of electrical stimulation (1 Hz) would be faster compared with that of C rats. Pm(O(2)) data were fit with a one or two exponential process (contingent on the presence of an undershoot) with independent time delays using least-squares regression analysis. In D rats, Pm(O(2)) at rest was lower (C 31.2 +/- 3.2 mmHg; D 24.3 +/- 1.3 mmHg, P < 0.05) and at the onset of contractions decreased after a shorter delay (C 13.5 +/- 1.8 s; D 7.6 +/- 2.1 s, P < 0.05) and with a reduced mean response time (C 31.4 +/- 3.3 s; D 23.9 +/- 3.1 s, P < 0.05). Pm(O(2)) exhibited a marked undershoot of the end-stimulation response in D muscles (D 3.3 +/- 1.1 mmHg, P < 0.05), which was absent in C muscles. These results indicate an altered VO(2)-to-QO(2) matching across the rest-exercise transition in muscles of D rats.
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Bases de datos:
MEDLINE
Asunto principal:
Oxígeno
/
Músculo Esquelético
/
Diabetes Mellitus Experimental
/
Contracción Muscular
Límite:
Animals
Idioma:
En
Revista:
Am J Physiol Heart Circ Physiol
Asunto de la revista:
CARDIOLOGIA
/
FISIOLOGIA
Año:
2002
Tipo del documento:
Article
País de afiliación:
Estados Unidos