Uneven perfusion within single cat muscles: Nitric oxide and citrate synthase play no role

Iversen, Per Ole; Flatebø, Torun; Nicolaysen, Gunnar

doi:10.1016/0034-5687(92)90091-a

Cited by 10 publications

(8 citation statements)

References 19 publications

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“…However, the present results showed that skewness and kurtosis of Q scan data were not affected by either L L -arg analogue, suggesting that the spatial heterogeneity of diaphragmatic microcirculation cannot be ascribed to a cross-sectional gradient in basal NO activity. Similar phenomena have been observed in both the canine hearts and cat hindlimbs, where blockade of local NO production had only minimal effects on the spatial heterogeneity of blood flow [39,40].…”

Section: Discussionsupporting

confidence: 67%

The role of nitric oxide in the spatial heterogeneity of basal microvascular blood flow in the rat diaphragm

et al. 2005

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The effects of N omega-nitro-L: -arginine (L: -NOARG) and N(G)-monomethyl-L: -arginine (L: -NMMA) on the spatial distribution of diaphragmatic microvascular blood flow were assessed in anesthetized, mechanically ventilated rats. Microvascular blood flow was measured after different periods at either a fixed site (Q stat) or 25 different sites (Q scan) using computer-aided laser-Doppler flowmetry (LDF) scanning. The value of Q stat was unaffected after 15-20 min superfusion with any one of the following agents: L: -NOARG (0.1 mM), L: -NMMA (0.1 mM), L: -arg (10 mM). The cumulative frequency histogram of the Q scan value in the control group displayed a non-Gaussian distribution that was not significantly affected after 15 min superfusion with the vehicle of L: -NOARG. Superfusion with either L: -NMMA or L: -NOARG at 0.1 mM for 15 min displaced the histogram of cumulative frequency to the left, with the median value of blood flow decreasing by 10 to 20%. However, skewness and kurtosis of the distribution of basal Q(scan) were unaffected after superfusion of either of the L: -arg analogues. Pretreatment with L: -arg (10 mM), followed by co-administration of L: -arg (10 mM) with L: -NOARG (0.1 mM) only partially prevented L: -NOARG from exerting this inhibitory effect on the distribution of basal Q scan, while pretreatment with L: -arg in the same manner could prevent L: -NMMA from exerting its inhibitory effect. There was a weak but significant linear relationship between the magnitude of basal Q(scan) and normalized changes in basal Q scan after superfusion of either of the L: -arg analogues. In conclusion, a basal NO activity is present in the diaphragmatic microvascular bed of rats. LDF scanning rather may yield more vivid information about the extent of overall tissue perfusion than conventional LDF whenever basal NO activity is involved. Moreover, the parallel flow profiles after NO synthase blockade suggest that the spatial inhomogeneity of basal diaphragmatic microvascular blood flow is not dependent on basal NO formation.

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Section: Discussionsupporting

confidence: 67%

The role of nitric oxide in the spatial heterogeneity of basal microvascular blood flow in the rat diaphragm

et al. 2005

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“…The role of NO in the regulation of local blood flow and blood flow distribution has been studied previously in animals in skeletal (24) and cardiac (13) muscle. Iversen and colleagues (24) studied blood flow distribution in cat skeletal muscle at rest and during exercise both without and with NO inhibition induced by L-NMMA and during reversal by L-arginine.…”

Section: Discussionmentioning

confidence: 99%

“…Previously, Iversen and coworkers studied the role of various physiological stimuli on skeletal muscle perfusion heterogeneity in different animals (24 -26, 28). One hypothesis tested was that nitric oxide (NO)-mediated vasodilation could play a role in the regulation of blood flow heterogeneity, but blocking of NO formation with N G -monomethyl-L-arginine (L-NMMA) had no influence (24). Blockade of NO formation alone has a variable, if any, effect on whole muscle blood flow during exercise in humans (17,46,50,53), but, with combined inhibition of NO and PGs (8,50) or endothelium-derived hyperpolarizing factor (EDHF; see Ref.…”

mentioning

confidence: 99%

Nitric oxide and prostaglandins influence local skeletal muscle blood flow during exercise in humans: coupling between local substrate uptake and blood flow

Kalliokoski¹,

Langberg²,

Ryberg³

et al. 2006

American Journal of Physiology-Regulatory, Integrative and Comp

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Synergic action of nitric oxide (NO) and prostaglandins (PG) in the regulation of muscle blood flow during exercise has been demonstrated. In the present study, we investigated whether these vasodilators also regulate local blood flow, flow heterogeneity, and glucose uptake within the exercising skeletal muscle. Skeletal muscle blood flow was measured in seven healthy young men using near-infrared spectroscopy and indocyanine green and muscle glucose uptake using positron emission tomography and 2-fluoro-2-deoxy-D-[(18)F]glucose without and with local blockade of NO and PG at rest and during one-legged dynamic knee-extension exercise. Local blockade was produced by infusing nitro-L-arginine methyl ester and indomethacin directly in the muscle via a microdialysis catheter. Blood flow and glucose uptake were measured in the region of blockade and in two additional regions of vastus lateralis muscle 1 and 4 cm away from the infusion of blockers. Local blockade during exercise at 25 and 40 watts significantly decreased blood flow in the infusion region and in the region 1 cm away from the site of infusion but not in the region 4 cm away. During exercise, muscle glucose uptake did not show any regional differences in response to blockade. These results show that NO and PG synergistically contribute to the local regulation of blood flow in skeletal muscle independently of muscle glucose uptake in healthy young men. Thus these vasodilators can play a role in regulating microvascular blood flow in localized regions of vastus lateralis muscle but do not influence regional glucose uptake. The findings suggest that local substrate uptake in skeletal muscle can be regulated independently of regional changes in blood flow.

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“…Evidently, at the whole body and whole limb level (3,47), matching is almost perfect. However, few studies examining this between or within muscles have shown poor local match (19,18,41,45,37,23).…”

mentioning

confidence: 99%

“…Matching between delivery (muscle perfusion) and needs (metabolic activity) has previously been studied by correlating different measures of local metabolic activity to local perfusion (19,18,23,37,41,45); the correlation between local muscle perfusion and glucose uptake (19) or citrate synthase activity (18) was poor at rest and only moderate during exercise. In recent human studies, relatively good correlation was found between local perfusion and oxygen uptake in different muscles of quadriceps femoris (QF) muscle group (23) and between different regions of QF muscle group in proximal to distal direction (37).…”

mentioning

confidence: 99%

Relationship between local perfusion and FFA uptake in human skeletal muscle—no effect of increased physical activity and aerobic fitness

Hannukainen¹,

Nuutila²,

Kaprio³

et al. 2006

Journal of Applied Physiology

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We investigated heredity-independent effects of increased physical activity and aerobic fitness on skeletal muscle free fatty acid (FFA) uptake, perfusion, and their heterogeneity at rest and during exercise. Also, the relationship between local skeletal muscle FFA uptake and perfusion was studied. Nine young adult male monozygotic twin pairs with significant difference in physical activity [229 min (SD 156) average time spent for conditioning exercise per week in more and 98 min (SD 71) in less active twins, P = 0.013] and aerobic fitness [18% (SD 10) difference in maximum O2 uptake] between brothers were studied using positron emission tomography. Submaximal knee-extension exercise increased perfusion, FFA uptake, and oxygen uptake in quadriceps femoris muscles 6-10 times compared with resting values (P < 0.001). More active twins tended to utilize more oxygen, while no differences were found in muscle perfusion or FFA uptake between groups. Mean perfusion and FFA uptake correlated strongly at a whole muscle level, both at rest (r = 0.97, P = 0.03 in more and r = 0.98, P = 0.02 in less active twins) and during exercise (r = 0.99, P = 0.01 and r = 0.94, P = 0.06), but at the voxel level (87 mm3) correlation was only moderate during exercise [r = 0.73 (SD 0.08) vs. r = 0.74 (SD 0.10), P = 0.92] and weak at rest [r = 0.28 (SD 0.13) vs. r = 0.33 (SD 0.21), P = 0.58]. Exercise decreased both perfusion and FFA uptake heterogeneity within the muscles (P < 0.001) similarly in both groups. In conclusion, long-term history of moderately increased physical activity tends to enhance muscle oxidative metabolism, but it does not have any significant influence on the FFA uptake or perfusion rates or their heterogeneity in skeletal muscle. Submaximal knee-extension exercise decreases heterogeneity of muscle FFA uptake and perfusion and improves matching between local muscle perfusion and FFA uptake. Thus it seems that the genetic influence is more important to determine the heterogeneity of perfusion and FFA uptake in skeletal muscle than exercise training.

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Uneven perfusion within single cat muscles: Nitric oxide and citrate synthase play no role

Cited by 10 publications

References 19 publications

The role of nitric oxide in the spatial heterogeneity of basal microvascular blood flow in the rat diaphragm

The role of nitric oxide in the spatial heterogeneity of basal microvascular blood flow in the rat diaphragm

Nitric oxide and prostaglandins influence local skeletal muscle blood flow during exercise in humans: coupling between local substrate uptake and blood flow

Relationship between local perfusion and FFA uptake in human skeletal muscle—no effect of increased physical activity and aerobic fitness

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