Muscle blood flow in cats: comparison of microdialysis ethanol technique with direct measurement

1995 ◽  
Vol 79 (2) ◽  
pp. 638-647 ◽  
Author(s):  
R. C. Hickner ◽  
U. Ekelund ◽  
S. Mellander ◽  
U. Ungerstedt ◽  
J. Henriksson
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Roller Pump ◽  
Perfusion Flow ◽  
Quantitative Validation ◽  
Nonlinear Fashion ◽  
Perfusion Flow Rate ◽  
Krebs Henseleit Buffer

A quantitative validation of the microdialysis ethanol technique was performed in cat gastrocnemius muscle. Six to eight microdialysis probes were inserted into the isolated muscle preparation and perfused (0.5–10.0 microliters/min) with Krebs-Henseleit buffer containing between 5 and 1,000 mmol/l ethanol. Skeletal muscle blood flow was held constant in the range of 4–99 ml.100 g-1.min-1 by a servo-controlled roller pump and was determined with the microdialysis ethanol technique as well as by timed collection of venous outflow. The ethanol concentration outflow-to-inflow ratio ([ethanol]collected dialysate/[ethanol]infused perfusion medium) decreased in a nonlinear fashion when microdialysis perfusion flow rates of 0.5 and 1.0 microliter/min were employed. However, a linear decrease was found between 4 and approximately 45 ml.100 g-1.min-1 (r = -0.92 to -0.99). The lower outflow-to-inflow ratio was at 4 ml.100 g-1.min-1 (i.e., due to a low probe perfusion flow rate or a large dialysis membrane), the greater the sensitivity of the method was. It is concluded that this nonradioactive technique provides a simple and valid method for determining nutritive blood flow in skeletal muscle.

Enhanced arteriolar α-adrenergic constriction impairs dilator responses and skeletal muscle perfusion in obese Zucker rats

2004 ◽  
Vol 97 (2) ◽  
pp. 764-772 ◽  
Author(s):  
Jefferson C. Frisbee
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Zucker Rats ◽  
Metabolic Demand ◽  
Obese Zucker Rats ◽  
Isometric Twitch ◽  
Gastrocnemius Muscles

The present study tested the hypothesis that enhanced vascular α-adrenergic constriction in obese Zucker rats (OZR) impairs arteriolar dilation and perfusion of skeletal muscle at rest and with increased metabolic demand. In lean Zucker rats (LZR) and OZR, isolated gracilis arterioles were viewed via television microscopy, and the contralateral cremaster muscle or gastrocnemius muscle was prepared for study in situ. Gracilis and cremasteric arterioles were challenged with dilator stimuli under control conditions and after blockade of α-adrenoreceptors with prazosin, phentolamine, or yohimbine. Gastrocnemius muscles performed isometric twitch contractions of increasing frequency, and perfusion was continuously monitored. In OZR, dilator responses of arterioles to hypoxia (gracilis), wall shear rate (cremaster), acetylcholine, and iloprost (both) were impaired vs. LZR. Treatment with prazosin and phentolamine (and in cremasteric arterioles only, yohimbine) improved arteriolar reactivity to these stimuli in OZR, although responses remained impaired vs. LZR. Gastrocnemius muscle blood flow was reduced at rest in OZR; this was corrected with intravenous infusion of phentolamine or prazosin. At all contraction frequencies, blood flow was reduced in OZR vs. LZR; this was improved by infusion of phentolamine or prazosin at low-moderate metabolic demand only (1 and 3 Hz). At 5 Hz, adrenoreceptor blockade did not alter blood flow in OZR from levels in untreated rats. These results suggest that enhanced α-adrenergic constriction of arterioles of OZR contributes to impaired dilator responses and reduced muscle blood flow at rest and with mild-moderate (although not with large) elevations in metabolic demand.

scholarly journals Nonuniform effects of endurance exercise training on vasodilation in rat skeletal muscle

2005 ◽  
Vol 98 (2) ◽  
pp. 753-761 ◽  
Author(s):  
R. M. McAllister ◽  
J. L. Jasperse ◽  
M. H. Laughlin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Training ◽  
Endurance Exercise ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Second Order ◽  
Skeletal Muscle Blood Flow ◽  
Endurance Exercise Training

Endurance exercise training (Ex) has been shown to increase maximal skeletal muscle blood flow. The purpose of this study was to test the hypothesis that increased endothelium-dependent vasodilation is associated with the Ex-induced increase in muscle blood flow. Furthermore, we hypothesized that enhanced endothelium-dependent dilation is confined to vessels in high-oxidative muscles that are recruited during Ex. To test these hypotheses, sedentary (Sed) and rats that underwent Ex (30 m/min × 10% grade, 60 min/day, 5 days/wk, 8–12 wk) were studied using three experimental approaches. Training effectiveness was evidenced by increased citrate synthase activity in soleus and vastus lateralis (red section) muscles ( P < 0.05). Vasodilatory responses to the endothelium-dependent agent acetylcholine (ACh) in situ tended to be augmented by training in the red section of gastrocnemius muscle (RG; Sed: control, 0.69 ± 0.12; ACh, 1.25 ± 0.15; Ex: control, 0.86 ± 0.17; ACh, 1.76 ± 0.27 ml·min−1·100 g−1·mmHg−1; 0.05 < P < 0.10 for Ex vs. Sed during ACh). Responses to ACh in situ did not differ between Sed and Ex for either the soleus muscle or white section of gastrocnemius muscle (WG). Dilatory responses of second-order arterioles from the RG in vitro to flow (4–8 μl/min) and sodium nitroprusside (SNP; 10−7 through10−4 M), but not ACh, were augmented in Ex (vs. Sed; P < 0.05). Dilatory responses to ACh, flow, and SNP of arterioles from soleus and WG muscles did not differ between Sed and Ex. Content of the endothelial isoform of nitric oxide synthase (eNOS) was increased in second-order, fourth-order, and fifth-order arterioles from the RG of Ex; eNOS content was similar between Sed and Ex in vessels from the soleus and WG muscles. These findings indicate that Ex induces endothelial adaptations in fast-twitch, oxidative, glycolytic skeletal muscle. These adaptations may contribute to enhanced skeletal muscle blood flow in endurance-trained individuals.

Endothelial modulation of skeletal muscle blood flow andV˙o 2 during low- and high-intensity contractions

2002 ◽  
Vol 92 (2) ◽  
pp. 461-468 ◽  
Author(s):  
Cheryl E. King-VanVlack ◽  
J. D. Mewburn ◽  
C. K. Chapler ◽  
P. H. MacDonald
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Methyl Ester ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Tension Development ◽  
Anesthetized Dogs ◽  
Isometric Twitch ◽  
Oxide Synthase

In the present study, we determined whether endothelin (ET)-1 contributed to the observed reduction in muscle blood flow (Q˙) during contractions with nitric oxide synthase (NOS) inhibition and whether muscle O2 uptake (V˙o 2) would be affected by the decrease in muscle Q˙ with NOS inhibition at different contraction intensities. Muscle Q˙,V˙o 2, O2 extraction ratio (OER), and tension development (TD) were studied in the in situ gastrocnemius muscle preparation in anesthetized dogs. A decrease in the V˙o 2-to-TD ratio (V˙o 2/TD) was used as an indicator of O2 limitation. Three contraction protocols were used: 1) isometric twitch contractions at 2 twitches (tw)/s, 2) the same contractions at 4 tw/s, and 3) pretreatment with an ETA-receptor antagonist (BQ-123) before 2 tw/s contractions. The muscle was stimulated to contract, and measures were obtained at steady state (∼5–8 min). NOS inhibition ( N ω-nitro-l-arginine methyl ester) was then induced, and measures were repeated at 2, 5, 10, and 15 min. During 2 tw/s contractions, NOS inhibition reduced Q˙with and without ETA-receptor blockade. In both groups, OER increased in response to the fall in Q˙, with the result being no change in V˙o 2/TD. NOS inhibition also decreased Q˙ during 4 tw/s contractions, but OER did not increase, resulting in a reduction inV˙o 2/TD 5 and 15 min after N ω-nitro-l-arginine methyl ester. These data indicated that 1) a reciprocal increase in ET-1 during NOS inhibition does not influence active hyperemia in skeletal muscle, and 2) during 4 tw/s contractions, the ischemia with NOS inhibition was associated with either an O2 limitation or an alteration in the efficiency of muscle contractions.

Diaphragm arterioles are less responsive to α1- adrenergic constriction than gastrocnemius arterioles

2002 ◽  
Vol 92 (5) ◽  
pp. 1808-1816 ◽  
Author(s):  
Aaron Aaker ◽  
M. H. Laughlin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Gastrocnemius Muscle ◽  
Fiber Type ◽  
Muscle Blood Flow ◽  
Oxidative Capacity ◽  
Receptor Stimulation ◽  
Exercise Induced ◽  
Fast Twitch

The sympathetic nervous system has greater influence on vascular resistance in low-oxidative, fast-twitch skeletal muscle than in high-oxidative skeletal muscle (17). The purpose of this study was to test the hypothesis that arterioles isolated from low-oxidative, fast-twitch skeletal muscle [the white portion of gastrocnemius (WG)] possess greater responsiveness to adrenergic constriction than arterioles isolated from high-oxidative skeletal muscle [red portion of the gastrocnemius muscle (RG) and diaphragm (Dia)]. Second-order arterioles (2As) were isolated from WG, RG, and Dia of rats and reactivity examined in vitro. Results reveal that Dia 2As constrict less to norepinephrine (NE) (10−9 to 10 −4 M) than 2As from RG and WG, which exhibited similar NE-induced constrictions. This difference was not endothelium dependent, because responses of denuded 2As were similar to those of intact arterioles. The blunted NE-induced constrictor response of Dia 2As appears to be the result of differences in α1-receptor effects because 1) arterioles from Dia also responded less to selective α1-receptor stimulation with phenylephrine than RG and WG arterioles; 2) arterioles from Dia, RG, and WG dilated similarly to isoproterenol (10−9 to 10−4 M) and did not respond to selective α2-receptor stimulation with UK-14304; and 3) endothelin-1 produced similar constriction in 2As from Dia, RG, and WG. We conclude that differences in oxidative capacity and/or fiber type composition of muscle tissue do not explain different NE responsiveness of Dia 2As compared with 2As from gastrocnemius muscle. Differences in α1-adrenergic constrictor responsiveness among arterioles in skeletal muscle may contribute to nonuniform muscle blood flow responses observed during exercise and serve to maintain blood flow to Dia during exercise-induced increases in sympathetic nerve activity.

scholarly journals Effects of aging and exercise training on skeletal muscle blood flow and resistance artery morphology

2012 ◽  
Vol 113 (11) ◽  
pp. 1699-1708 ◽  
Author(s):  
Bradley J. Behnke ◽  
Michael W. Ramsey ◽  
John N. Stabley ◽  
James M. Dominguez ◽  
Robert T. Davis ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Training ◽  
Old Age ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Resistance Artery ◽  
Cross Sectional ◽  
Age Related ◽  
Feed Arteries

With old age, blood flow to the high-oxidative red skeletal muscle is reduced and blood flow to the low-oxidative white muscle is elevated during exercise. Changes in the number of feed arteries perforating the muscle are thought to contribute to this altered hyperemic response during exercise. We tested the hypothesis that exercise training would ameliorate age-related differences in blood flow during exercise and feed artery structure in skeletal muscle. Young (6–7 mo old, n = 36) and old (24 mo old, n = 25) male Fischer 344 rats were divided into young sedentary (Sed), old Sed, young exercise-trained (ET), and old ET groups, where training consisted of 10–12 wk of treadmill exercise. In Sed and ET rats, blood flow to the red and white portions of the gastrocnemius muscle (GastRed and GastWhite) and the number and luminal cross-sectional area (CSA) of all feed arteries perforating the muscle were measured at rest and during exercise. In the old ET group, blood flow was greater to GastRed (264 ± 13 and 195 ± 9 ml·min−1·100 g−1 in old ET and old Sed, respectively) and lower to GastWhite (78 ± 5 and 120 ± 6 ml·min−1·100 g−1 in old ET and old Sed, respectively) than in the old Sed group. There was no difference in the number of feed arteries between the old ET and old Sed group, although the CSA of feed arteries from old ET rats was larger. In young ET rats, there was an increase in the number of feed arteries perforating the muscle. Exercise training mitigated old age-associated differences in blood flow during exercise within gastrocnemius muscle. However, training-induced adaptations in resistance artery morphology differed between young (increase in feed artery number) and old (increase in artery CSA) animals. The altered blood flow pattern induced by exercise training with old age would improve the local matching of O2 delivery to consumption within the skeletal muscle.

Neural control of glucose uptake by skeletal muscle after central administration of NMDA

1995 ◽  
Vol 268 (2) ◽  
pp. R492-R497 ◽  
Author(s):  
C. H. Lang ◽  
M. Ajmal ◽  
A. G. Baillie
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Glucose Uptake ◽  
Neural Control ◽  
Plasma Insulin ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Whole Body ◽  
Glucose Disposal ◽  
Central Administration

Intracerebroventricular injection of N-methyl-D-aspartate (NMDA) produces hyperglycemia and increases whole body glucose uptake. The purpose of the present study was to determine in rats which tissues are responsible for the elevated rate of glucose disposal. NMDA was injected intracerebroventricularly, and the glucose metabolic rate (Rg) was determined for individual tissues 20-60 min later using 2-deoxy-D-[U-14C]glucose. NMDA decreased Rg in skin, ileum, lung, and liver (30-35%) compared with time-matched control animals. In contrast, Rg in skeletal muscle and heart was increased 150-160%. This increased Rg was not due to an elevation in plasma insulin concentrations. In subsequent studies, the sciatic nerve in one leg was cut 4 h before injection of NMDA. NMDA increased Rg in the gastrocnemius (149%) and soleus (220%) in the innervated leg. However, Rg was not increased after NMDA in contralateral muscles from the denervated limb. Data from a third series of experiments indicated that the NMDA-induced increase in Rg by innervated muscle and its abolition in the denervated muscle were not due to changes in muscle blood flow. The results of the present study indicate that 1) central administration of NMDA increases whole body glucose uptake by preferentially stimulating glucose uptake by skeletal muscle, and 2) the enhanced glucose uptake by muscle is neurally mediated and independent of changes in either the plasma insulin concentration or regional blood flow.

scholarly journals Sequential alterations in the diameters of capillaries in rabbit skeletal muscle following deep transverse friction - a morphometric study

2005 ◽  
Vol 61 (2) ◽  
Author(s):  
M. A. Gregory ◽  
M. N. Deane ◽  
M. Marsh
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Blood Flow ◽  
Biceps Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Biceps Femoris Muscle ◽  
Beneficial Effects ◽  
The Cross

Objective: The precise mechanisms by which massage promotes repair in injured soft tissue are unknown. Various authorshave attributed the beneficial effects of massage to vasodilation and increased skin and muscle blood flow. The aim of this study was to determine whether deep transverse friction massage (DTF) causes capillary vasodilation in untraumatised skeletal muscle. Setting: Academic institution.Interventions: Twelve New Zealand white rabbits were anaesthetised and the left biceps femoris muscle received 10 minutes of DTF. Following treatment, wedge biopsies were taken from the musclewithin 10 minutes of treatment (R1 - 4), 24 hours (R5 - 8) and 6 days(R9 - 12) after treatment. To serve as controls, similar biopsies weretaken from the right biceps femoris of animals. The samples were fixed, dehydrated and embedded in epoxy resin.Transverse sections (1µm) of muscle were cut, stained with 1% aqueous alkaline toluidine blue and examined with a light microscope using a 40X objective. Images containing capillaries were captured using an image analyser with SIS software and the cross sectional diameters of at least 60 capillaries were measured from each specimen. Main Outcome Measures: Changes in capillary diameter. Results: The mean capillary diameters in control muscle averaged 4.76 µm. DTF caused a significant immediate increase of 17.3% in cross sectional area (p<0.001), which was not significantly increased by 10.0% after 24 hours (p>0.05). Six days after treatment the cross-sectional area of the treated muscle was 7.6% smaller than the controls. Conclusions: This confirms the contention that DTF stimulates muscle blood flow immediately after treatment and this may account for its beneficial effects in certain conditions. 

Relation of blood flow to VO2, PO2, and PCO2 in dog gastrocnemius muscle

1988 ◽  
Vol 255 (5) ◽  
pp. H1004-H1010 ◽  
Author(s):  
D. E. Mohrman ◽  
R. R. Regal
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Carbon Dioxide Tension ◽  
Experimental Conditions ◽  
Muscle Oxygen ◽  
Muscle Oxygen Consumption ◽  
Relationship Of ◽  
The Relationship

We pump-perfused gastrocnemius-plantaris muscle preparations at constant pressure to study the relationship of muscle blood flow (Q) to muscle oxygen consumption (VO2), venous oxygen tension (PVO2), and venous carbon dioxide tension (PVCO2) during steady-state exercise at different rates. Tests were performed under four experimental conditions produced by altering the perfusate blood-gas status with a membrane lung. The consistency of the relationship of Q to other variables was evaluated by statistical analysis of fitted curves. Not one of the above listed variables had the same relationship with Q in all four of the experimental conditions we tested. However, we did find that a consistent relationship existed among Q, PVO2, and PVCO2 in our data. That relationship is well described by the equation (Q-23).[PVO2 - (0.5.PVCO2) - 3] = 105 (when Q is expressed in ml.100 g-1.min-1 and PVO2 and PVCO2 in mmHg). One interpretation of this result is that both PO2 and PCO2 are important variables in the control of blood flow in skeletal muscle the combined influence of which could account for nearly all of the hyperemia response to steady-state muscle exercise.

Biphasic effect of hydrogen peroxide on skeletal muscle arteriolar tone via activation of endothelial and smooth muscle signaling pathways

2004 ◽  
Vol 97 (3) ◽  
pp. 1130-1137 ◽  
Author(s):  
Csongor Csekő ◽  
Zsolt Bagi ◽  
Akos Koller
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Hydrogen Peroxide ◽  
Blood Flow ◽  
Smooth Muscle ◽  
Muscle Blood Flow ◽  
Skeletal Muscle Blood Flow ◽  
Local Regulation ◽  
Prostaglandin H ◽  
Arteriolar Tone

We hypothesized that hydrogen peroxide (H2O2) has a role in the local regulation of skeletal muscle blood flow, thus significantly affecting the myogenic tone of arterioles. In our study, we investigated the effects of exogenous H2O2 on the diameter of isolated, pressurized (at 80 mmHg) rat gracilis skeletal muscle arterioles (diameter of ∼150 μm). Lower concentrations of H2O2 (10−6–3 × 10−5 M) elicited constrictions, whereas higher concentrations of H2O2 (6 × 10−5–3 × 10−4 M), after initial constrictions, caused dilations of arterioles (at 10−4 M H2O2, −19 ± 1% constriction and 66 ± 4% dilation). Endothelium removal reduced both constrictions (to −10 ± 1%) and dilations (to 33 ± 3%) due to H2O2. Constrictions due to H2O2 were completely abolished by indomethacin and the prostaglandin H2/thromboxane A2 (PGH2/TxA2) receptor antagonist SQ-29548. Dilations due to H2O2 were significantly reduced by inhibition of nitric oxide synthase (to 38 ± 7%) but were unaffected by clotrimazole or sulfaphenazole (inhibitors of cytochrome P-450 enzymes), indomethacin, or SQ-29548. In endothelium-denuded arterioles, clotrimazole had no effect, whereas H2O2-induced dilations were significantly reduced by charybdotoxin plus apamin, inhibitors of Ca2+-activated K+ channels (to 24 ± 3%), the selective blocker of ATP-sensitive K+ channels glybenclamide (to 14 ± 2%), and the nonselective K+-channel inhibitor tetrabutylammonium (to −1 ± 1%). Thus exogenous administration of H2O2 elicits 1) release of PGH2/TxA2 from both endothelium and smooth muscle, 2) release of nitric oxide from the endothelium, and 3) activation of K+ channels, such as Ca2+-activated and ATP-sensitive K+ channels in the smooth muscle resulting in biphasic changes of arteriolar diameter. Because H2O2 at low micromolar concentrations activates several intrinsic mechanisms, we suggest that H2O2 contributes to the local regulation of skeletal muscle blood flow in various physiological and pathophysiological conditions.

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