Rat Muscle Blood Flows During High Speed Locomotion

Armstrong, R. B.; Phelps, R. O.; Rouk, K.; Stroup, Richard E.; White, Joshua Dylan; Laughlin, M. H.

doi:10.1249/00005768-198504000-00449

Cited by 36 publications

(54 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This environment, while inhibitory to NOS function, potentiates the reduction of NO 2 Ϫ to NO (10,14). In healthy rats, stronger fiber type correlations (r ϭ 0.74 and 0.71 for the change in BF and change in VC, respectively) were found after 5 days of NO 3 Ϫ supplementation with beetroot juice (18). It is possible that chronic exposure to an elevated NO 2 Ϫ concentration (e.g., days) may elicit a greater effect on skeletal muscle vascular function as this alters the expression of key Ca 2ϩ -handling proteins augmenting the contractile function of fast twitch, but not slow twitch, skeletal muscle (24).…”

Section: Impacts Of Nomentioning

confidence: 92%

“…NO is synthesized endogenously via three isoforms of NO synthase (NOS) as well as by the nonenzymatic reduction of NO 3 Ϫ to NO 2 Ϫ and, finally, to NO (for a review, see Ref. 38).…”

Section: New and Noteworthymentioning

confidence: 99%

“…Mechanistic investigations have revealed that NO 3 Ϫ supplementation increases exercising skeletal muscle blood flow (BF) (18), skeletal muscle microvascular PO 2 (17,19), and the rate of skeletal muscle force development (24), particularly in muscles composed of predominantly fast twitch fibers. This fiber type preferential effect is likely due to the lower PO 2 /pH environment in contracting fast twitch muscle (IIb ϩ IId/x fibers) (40), an environment exacerbated by CHF.…”

Section: New and Noteworthymentioning

confidence: 99%

“…Thus, a local shift to glycolytic metabolism accompanied by a rapid vasodilation within these tissues may account for the changes in blood lactate concentration seen herein. In addition, the small reductions in BF to muscles comprised predominantly of slow twitch fibers (e.g., red portion of the vastus lateralis) may have also stimulated increased lactate production as these muscles often require the highest absolute BF during exercise (3,36). However, it is worth mentioning that the lactate concentrations after NO 2 Ϫ infusion reported herein are well within reasonable ranges of what has been observed previously in our laboratory at this running speed (16,18,27), particularly in rats with CHF (28).…”

Section: Impacts Of Nomentioning

confidence: 99%

See 3 more Smart Citations

Effects of nitrite infusion on skeletal muscle vascular control during exercise in rats with chronic heart failure

Glean

Ferguson

Holdsworth

et al. 2015

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

Ϫ to NO may impact exercise-induced hyperemia, particularly in muscles with pathologically reduced O 2 delivery. We tested the hypothesis that NO 2 Ϫ infusion would increase exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats with a preferential effect in muscles composed primarily of type IIb ϩ IId/x fibers. CHF (coronary artery ligation) was induced in adult male Sprague-Dawley rats. After a Ͼ21-day recovery, mean arterial pressure (MAP; carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% incline) with and without NO 2 Ϫ infusion. The myocardial infarct size (35 Ϯ 3%) indicated moderate CHF. NO 2 Ϫ infusion increased total hindlimb skeletal muscle VC (CHF: 0.85 Ϯ 0.09 ml·min Ϫ1 ·100 g Ϫ1 ·mmHg Ϫ1 and CHF ϩ NO 2 Ϫ : 0.93 Ϯ 0.09 ml·min Ϫ1 ·100 g Ϫ1 ·mmHg Ϫ1 , P Ͻ 0.05) without changing MAP (CHF: 123 Ϯ 4 mmHg and CHF ϩ NO 2 Ϫ : 120 Ϯ 4 mmHg, P ϭ 0.17). Total hindlimb skeletal muscle BF was not significantly different (CHF: 102 Ϯ 7 and CHF ϩ NO 2 Ϫ : 109 Ϯ 7 ml·min Ϫ1 ·100 g Ϫ1 ml·min Ϫ1 ·100 g Ϫ1 , P Ͼ 0.05). BF increased in 6 (ϳ21%) and VC in 8 (ϳ29%) of the 28 individual muscles and muscle parts. Muscles and muscle portions exhibiting greater BF and VC after NO 2 Ϫ infusion comprised Ն63% type IIb ϩ IId/x muscle fibers. These data demonstrate that NO 2 Ϫ infusion can augment skeletal muscle vascular control during exercise in CHF rats. Given the targeted effects shown herein, a NO 2 Ϫ -based therapy may provide an attractive "needs-based" approach for treatment of the vascular dysfunction in CHF. CHRONIC HEART FAILURE (CHF) is characterized by a combination of central and peripheral circulatory dysfunction that ultimately impairs exercise tolerance and quality of life (30,47). About 23 million individuals worldwide suffer from this disease (37), and while central cardiac dysfunction is fundamental to the etiology of CHF, the peripheral vascular impairments induced by CHF are of paramount importance. CHFinduced vascular dysregulation is thought to be due, in part, to reduced nitric oxide (NO)-mediated function (Ref. 20; for a review, see Ref. 47). Although exercise rehabilitation represents an effective therapeutic modality for treating CHF (9), reduced NO bioavailability in CHF is associated with an impaired ability to perform exercise and/or even complete daily physical activities. Consequently, interventions that increase NO bioavailability may ameliorate the skeletal muscle vascular dysfunction evident in this disease (20,25) and thus have great potential to improve exercise tolerance and quality of life in this population.NO is synthesized endogenously via three isoforms of NO synthase (NOS) as well as by the nonenzymatic reduction of NO 3 Ϫ to NO 2 Ϫ and, finally, to NO (for a review, see Ref. 38). The contribution of the NO 3 Ϫ -NO 2 Ϫ -NO pathway can be upregulated when plasma NO 2 Ϫ concentration is increased either by dietary means (e.g., via beetroot juice) or direct venous or arterial NO 2 Ϫ...

show abstract

Section: Impacts Of Nomentioning

confidence: 92%

“…NO is synthesized endogenously via three isoforms of NO synthase (NOS) as well as by the nonenzymatic reduction of NO 3 Ϫ to NO 2 Ϫ and, finally, to NO (for a review, see Ref. 38).…”

Section: New and Noteworthymentioning

confidence: 99%

Section: New and Noteworthymentioning

confidence: 99%

Section: Impacts Of Nomentioning

confidence: 99%

See 2 more Smart Citations

Effects of nitrite infusion on skeletal muscle vascular control during exercise in rats with chronic heart failure

Glean

Ferguson

Holdsworth

et al. 2015

American Journal of Physiology-Heart and Circulatory Physiology

View full text Add to dashboard Cite

show abstract

“…Skeletal muscle blood flow increases in proportion to the metabolic demand. [33][34][35][36][37] The precise contribution of the various vasoactive compounds to exercise-induced vasorelaxation may also differ by muscle beds studied and involve the interaction of the autonomic nervous system. [37][38][39][40] Prostacyclins contribute modestly and transiently to exercise-induced vasodilation 20 and, for the purposes of this study, cyclooxygenase was inhibited prior to the study.…”

Section: No and Exercise-induced Vasodilationmentioning

confidence: 99%

Contribution of endothelium-derived hyperpolarizing factor to exercise-induced vasodilation in health and hypercholesterolemia

et al. 2015

View full text Add to dashboard Cite

The role of endothelium-derived hyperpolarizing factor (EDHF) in either the healthy circulation or in those with hypercholesterolemia is unknown. In healthy and hypercholesterolemic subjects, we measured forearm blood flow (FBF) using strain-gauge plethysmography at rest, during graded handgrip exercise, and after sodium nitroprusside infusion. Measurements were repeated after l-NMMA, tetraethylammonium (TEA), and combined infusions. At rest, l-NMMA infusion reduced FBF in healthy but not hypercholesterolemic subjects. At peak exercise, vasodilation was lower in hypercholesterolemic compared to healthy subjects (274% vs 438% increase in FBF, p=0.017). TEA infusion reduced exercise-induced vasodilation in both healthy and hypercholesterolemic subjects (27%, p<0.0001 and -20%, p<0.0001, respectively). The addition of l-NMMA to TEA further reduced FBF in healthy (-14%, p=0.012) but not in hypercholesterolemic subjects, indicating a reduced nitric oxide and greater EDHF-mediated contribution to exerciseinduced vasodilation in hypercholesterolemia. In conclusion, exercise-induced vasodilation is impaired and predominantly mediated by EDHF in hypercholesterolemic subjects. Clinical Trial Registration Identifier: NCT00166166

show abstract

Distribution of microspheres in plantaris muscles of resting and exercising rats as a function of fiber type

1988

Self Cite

View full text Add to dashboard Cite

The purpose of this study was to determine histologically the distribution of microspheres (MSs) (14 micron), and hence the relative distribution of blood flow, in rat plantaris muscle relative to the fiber types (fast-twitch-oxidative-glycolytic [FOG], fast-twitch-glycolytic [FG], and slow-twitch-oxidative [SO]). Three conditions were investigated: 1) preexercise standing; 2) treadmill locomotion at 15 m/min (fast walking); and 3) treadmill locomotion at 60 m/min (moderate galloping). The MS suspension (containing 1 x 10(6) MSs) was infused into the ascending aorta via a catheter in the carotid artery under each of the 3 conditions so that MSs were distributed to the tissues in proportion to their respective blood flows. Sections (20 micron) of the plantaris muscle were cut and assayed for reduced nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) and myofibrillar adenosine triphosphatase (ATPase) activities so the fibers could be typed as SO, FOG, or FG. MSs were located in the NADH-TR sections, and the fibers next to the MSs were classified and counted. The observed numbers of fibers of each type in each condition that were adjacent to MSs were compared to the predicted number of adjacent fibers based on the assumption the MSs were randomly distributed in the tissue. This analysis demonstrated that MSs (and blood flows) were preferentially distributed to SO fibers during preexercise, to SO and FOG fibers during slow locomotion, and to FOG fibers during fast locomotion. The data support the contention that blood flow is distributed in muscles of conscious animals as functions of fiber type and exercise intensity.

show abstract

Rat Muscle Blood Flows During High Speed Locomotion

Cited by 36 publications

References 0 publications

Effects of nitrite infusion on skeletal muscle vascular control during exercise in rats with chronic heart failure

Effects of nitrite infusion on skeletal muscle vascular control during exercise in rats with chronic heart failure

Contribution of endothelium-derived hyperpolarizing factor to exercise-induced vasodilation in health and hypercholesterolemia

Distribution of microspheres in plantaris muscles of resting and exercising rats as a function of fiber type

Contact Info

Product

Resources

About