Postnatal changes in regional blood flow during cold-induced shivering in sow-reared piglets

1999 ◽  
Vol 77 (6) ◽  
pp. 414-421 ◽  
Author(s):  
Gaëlle Lossec ◽  
Claude Duchamp ◽  
Yves Lebreton ◽  
Patrick Herpin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Heat Production ◽  
Cold Exposure ◽  
Cardiovascular Response ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Cold Challenge ◽  
Shivering Thermogenesis

To determine whether newborn pigs are able to display adequate cardiovascular adjustments favouring shivering thermogenesis in skeletal muscles soon after birth, regional blood flow and fractional distribution of cardiac output were determined in 1-day-old (n = 6) and 5-day-old (n = 6) conscious piglets at thermal neutrality and during cold exposure, using coloured microspheres. Five-day-old piglets stayed with the sow before the experiment. The cold challenge was designed to induce a similar increase (~+90%) in heat production at both ages. Skeletal muscle blood flow increased with both age (p < 0.05) and cold exposure (p < 0.001), with the effect of cold being more pronounced in 5-day-old piglets than in 1-day-old piglets (+60%, p < 0.05). The difference between individual muscles increased with age, with fractional blood flow being 41% higher in rhomboideus than in longissimus thoracis muscle during cold exposure in 5-day-old piglets (p < 0.05). Cardiac output was similar at both ages and increased by 23% in the cold (p < 0.001). At 1 day of age, there was no redistribution of cardiac output among the internal organs during the cold challenge, while at 5 days of age, the increase in muscle fractional blood flow was associated with a reduction (p < 0.05) in the fraction of cardiac output reaching the skin (-24%), the small intestine (-21%), and the liver (-20%). In conclusion, these results suggest that there is a rapid postnatal improvement of cardiovascular adjustments favouring blood perfusion and probably heat production during cold-induced shivering in the most oxidative muscles studied. This cardiovascular response may play a role in the postnatal enhancement of thermoregulation in piglets.Key words: skeletal muscle, blood distribution, shivering thermogenesis, piglet, age.

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.

Regional blood flows in salt loading hypertension in the dog

1981 ◽  
Vol 240 (3) ◽  
pp. H361-H367 ◽  
Author(s):  
J. F. Liard
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Muscle Blood Flow ◽  
Peripheral Resistance ◽  
Salt Loading ◽  
Skeletal Muscle Blood Flow ◽  
Blood Flows ◽  
Regional Blood Flows

An intravenous infusion of isotonic sodium chloride, 196 ml/kg per day, was administered for several days to eight dogs with their renal mass reduced. Mean arterial pressure, cardiac output (electromagnetic flowmeter), and regional blood flows (radioactive microspheres) were measured sequentially and the results compared with those obtained in six control dogs. The salt-loaded animals exhibited on the 1st day of the infusion a 25% increase of arterial pressure and cardiac output. Blood flows to the kidney, the splanchnic area, the skin, and the bone were not significantly changed, whereas skeletal muscle blood flow almost doubled. After several days, cardiac output returned toward control values but pressure remained elevated. Skeletal muscle blood flow, as most other regional flows, did not differ significantly from control values at that time. In four dogs studied 6 h after starting a faster saline infusion, most of the increase in cardiac output was also distributed to the skeletal muscle. Total peripheral resistance changes did not reflect the resistance of individual beds, because vasoconstriction appeared early in some areas but was masked by prominent, although transient, vasodilation in skeletal muscle.

scholarly journals Beneficial haemodynamic effects of insulin in chronic heart failure

Heart ◽  
2001 ◽  
Vol 85 (5) ◽  
pp. 508-513
Author(s):  
W A Parsonage ◽  
D Hetmanski ◽  
A J Cowley
Keyword(s):  
Heart Failure ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Chronic Heart Failure ◽  
Insulin Infusion ◽  
Muscle Blood Flow ◽  
Haemodynamic Effects ◽  
High Dose ◽  
Skeletal Muscle Blood Flow

OBJECTIVETo characterise the central and regional haemodynamic effects of insulin in patients with chronic heart failure.DESIGNSingle blind, placebo controlled study.SETTINGUniversity teaching hospital.PATIENTSTen patients with stable chronic heart failure.INTERVENTIONSHyperinsulinaemic euglycaemic clamp and non-invasive haemodynamic measurements.MAIN OUTCOME MEASURESChange in resting heart rate, blood pressure, cardiac output, and regional splanchnic and skeletal muscle blood flow.RESULTSInsulin infusion led to a dose dependent increase in skeletal muscle blood flow of 0.36 (0.13) and 0.73 (0.14) ml/dl/min during low and high dose insulin infusions (p < 0.05 and p < 0.005 v placebo, respectively). Low and high dose insulin infusions led to a fall in heart rate of 4.6 (1.4) and 5.1 (1.3) beats/min (p < 0.05 and p < 0.005 v placebo, respectively) and a modest increase in cardiac output. There was no significant change in superior mesenteric artery blood flow.CONCLUSIONIn patients with chronic heart failure insulin is a selective skeletal muscle vasodilator that leads to increased muscle perfusion primarily through redistribution of regional blood flow rather than by increased cardiac output. These results provide a rational haemodynamic explanation for the apparent beneficial effects of insulin infusion in the setting of heart failure.

Effects of high-intensity sprint training on skeletal muscle blood flow in rats

1991 ◽  
Vol 71 (4) ◽  
pp. 1387-1395 ◽  
Author(s):  
T. I. Musch ◽  
J. A. Terrell ◽  
M. R. Hilty
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
High Intensity ◽  
Maximal Exercise ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Female Rats ◽  
Sprint Training ◽  
Skeletal Muscle Blood Flow ◽  
Abdominal Region

The regional blood flow response (via radioactive microspheres) was determined for female rats after 6 wk of high-intensity sprint training (HIST) or limited cage activity as the animals exercised at work loads that would elicit maximal O2 uptake. Blood flow to the different organs of the abdominal region was greatly reduced during maximal exercise conditions, and the magnitude of the reduction appeared to be similar for both the HIST group of rats and their sedentary (SED) control counterparts. Of the 20 different hindlimb muscles examined in the present study, blood flow to the soleus, plantaris, gastrocnemius, flexor hallicus longus, vastus lateralis, rectus femoris, biceps femoris, and adductor magnus and brevis muscles was significantly greater (P less than 0.05) in the HIST rats during maximal exercise conditions than in the SED control rats. Correspondingly, blood flow to the total hindlimb during maximal exercise was also significantly greater in the HIST rats than in the SED control rats [240 +/- 18 vs. 192 +/- 15 (SE) ml.min-1.100 g-1]. These results support the contention that the increase in maximal cardiac output that is produced by HIST in the rat is primarily directed toward the working skeletal muscle and not toward the organs found in the abdominal region. We conclude from these experiments that HIST will produce significant adaptations in central cardiac function and skeletal muscle blood flow in the rat.

Effect of enkephalins on cardiac output and regional blood flow in conscious dogs

1989 ◽  
Vol 256 (6) ◽  
pp. H1651-H1658
Author(s):  
C. L. Rosen ◽  
A. Cote ◽  
G. G. Haddad
Keyword(s):  
Skeletal Muscle ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Base Line ◽  
Brain Blood Flow ◽  
O2 Consumption ◽  
Blood Gas ◽  
Blood Flow Redistribution

To investigate the effects of enkephalins on cardiac output and regional blood flow, we administered D-Ala-D-Leu-enkephalin (DADLE) intracisternally (ic) to 14 chronically instrumented unanesthetized dogs. Measurements were made at base line, 20, 45, and 75 min after DADLE (25 or 125 micrograms/kg) and 15 min after naloxone (5 micrograms/kg ic). After 125 micrograms/kg DADLE, all animals developed hypoventilation, bradycardia, and decreased O2 consumption without hypotension. Cardiac output decreased (-34%), but brain blood flow increased (+110%). Blood flow decreased to the diaphragm (-38%), heart (-21%), skeletal muscle (-40%), skin (-67%), pancreas (-79%), and gastrointestinal tract (-26%). After 25 micrograms/kg DADLE, there were no consistent changes in cardiac output or regional blood flow. Four additional animals (without DADLE) were exposed to altered inspired gases to reproduce the blood gas changes after DADLE. These animals developed hyperventilation without bradycardia and increased brain (+114%) and diaphragm (+649%) blood flow. We conclude that centrally administered enkephalins produce 1) a parallel decrease in ventilation, heart rate, O2 consumption, and cardiac output and 2) a major blood flow redistribution, primarily dictated by the effects of opioids on ventilation, heart rate, and metabolism.

Skeletal muscle as the major site of nonshivering thermogenesis in cold-acclimated ducklings

1993 ◽  
Vol 265 (5) ◽  
pp. R1076-R1083 ◽  
Author(s):  
C. Duchamp ◽  
H. Barre
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cold Exposure ◽  
Muscle Blood Flow ◽  
Arterial Blood Flow ◽  
O2 Consumption ◽  
Nonshivering Thermogenesis ◽  
Arterial Blood ◽  
Brown Adipose ◽  
Leg Muscle

Despite their lack of brown adipose tissue, 6-wk-old cold-acclimated muscovy ducklings (4 degrees C; CA) exhibit nonshivering thermogenesis (NST) in the cold. To determine the site of this NST, the regional distribution of blood flow was measured by the microsphere method in the thermoneutral zone (25 degrees C) and during acute exposure to cold (8 degrees C). Ducklings reared at thermal neutrality (TN), which use shivering to produce extra heat in the cold, were compared with CA ducklings, which substitute NST for shivering. Further, the contribution of skeletal muscle thermogenesis to the increased heat production in the cold was estimated by measuring leg muscle blood flow and arteriovenous difference in oxygen content [(a-v)O2] across the leg, enabling an estimation of muscle O2 consumption. During cold exposure, a similar increase in total leg muscle blood flow occurred in TN and CA ducklings (+127 and +130% respectively), while hepatic arterial blood flow increased less (+56 to +37%, respectively). This rise in blood flow was accounted for by an increase in cardiac output, which was smaller in CA than in TN ducklings, and in both groups by a redistribution of blood flow to the most thermogenic organs (skeletal muscles and liver). The (a-v)O2 across the leg was not changed by cold exposure, indicating that the increase in leg muscle O2 consumption resulted mainly from the increase in blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Cardiovascular control during whole body exercise

2016 ◽  
Vol 121 (2) ◽  
pp. 376-390 ◽  
Author(s):  
Stefanos Volianitis ◽  
Niels H. Secher
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Peripheral Resistance ◽  
Muscle Group ◽  
Whole Body ◽  
Muscle Groups ◽  
Exercise Muscle

It has been considered whether during whole body exercise the increase in cardiac output is large enough to support skeletal muscle blood flow. This review addresses four lines of evidence for a flow limitation to skeletal muscles during whole body exercise. First, even though during exercise the blood flow achieved by the arms is lower than that achieved by the legs (∼160 vs. ∼385 ml·min−1·100 g−1), the muscle mass that can be perfused with such flow is limited by the capacity to increase cardiac output (42 l/min, highest recorded value). Secondly, activation of the exercise pressor reflex during fatiguing work with one muscle group limits flow to other muscle groups. Another line of evidence comes from evaluation of regional blood flow during exercise where there is a discrepancy between flow to a muscle group when it is working exclusively and when it works together with other muscles. Finally, regulation of peripheral resistance by sympathetic vasoconstriction in active muscles by the arterial baroreflex is critical for blood pressure regulation during exercise. Together, these findings indicate that during whole body exercise muscle blood flow is subordinate to the control of blood pressure.

Alterations in distribution of cardiac output in experimental diabetes in rats

1989 ◽  
Vol 257 (2) ◽  
pp. H571-H580 ◽  
Author(s):  
M. A. Hill ◽  
R. G. Larkins
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Output ◽  
Cardiac Index ◽  
Regional Blood Flow ◽  
Flow Distribution ◽  
Body Weight Loss ◽  
Abdominal Organs ◽  
Thoracic And Abdominal

Alterations in blood flow distribution in streptozotocin-induced diabetes in the rat were examined. Blood flow between tissues was estimated by the distribution of radiolabeled microspheres, and a second series of experiments examined skeletal muscle microcirculation by in vivo microscopy. Studies were performed in anesthetized rats 1-8 wk after induction of diabetes. Cardiac index was transiently increased in diabetic animals (29.6 +/- 1.0 ml.min-1.100 g-1) in comparison with control animals (23.0 +/- 1.4 ml.min-1.100 g-1) at 2-wk duration. Cardiac index was similar in both groups of animals at all other time points studied. The increased cardiac index coincided with transiently increased blood flow to diaphragm and abdominal wall and a significant vasodilatation of small cremaster muscle arterioles. Blood flow to skin and some skeletal muscles was thereafter significantly decreased in the diabetic animals. Blood flow (ml.min-1.100 g-1) to the brain and main thoracic and abdominal organs was similar in nonfasting control and diabetic animals throughout the period of study. As a result of hyperplasia, blood flow to the small intestine (%cardiac output) was increased in the diabetic animals (at 4 wk of diabetes, 34.5 +/- 2.1 vs. 17.5 +/- 0.8%, P less than 0.001). Despite reduction in blood flow to the intestine, by dietary restriction, flow to skin and skeletal muscle remained significantly decreased. Insulin treatment, at a dose aimed at preventing body weight loss but maintaining hyperglycemia, led to renal hyperperfusion in comparison with untreated diabetic and control animals. The alterations in regional blood flow appear progressive in nature and are not simply related to each other but may reflect tissue adaptation to the metabolic disorder.

Regional Blood Flow in Borderline and Sustained Essential Hypertension

1981 ◽  
Vol 60 (6) ◽  
pp. 653-658 ◽  
Author(s):  
M. M. Temmar ◽  
M. E. Safar ◽  
J. A. Levenson ◽  
J. M. Totomoukouo ◽  
A. Ch. Simon
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Essential Hypertension ◽  
Lower Limb ◽  
Regional Blood Flow ◽  
Muscle Blood Flow ◽  
Limb Blood Flow ◽  
Normal Range ◽  
Borderline Hypertension ◽  
Blood Flows

1. Cardiac output, lower-limb blood flow, hepatic and renal blood flows were studied in 16 patients with borderline and 16 patients with sustained essential hypertension and compared with 16 age-matched control subjects. 2. In borderline hypertension cardiac output and lower-limb blood flow were significantly elevated, while hepatic and renal blood flows were within the normal range. Cardiac output and lower-limb blood flow were positively correlated. 3. In sustained hypertension cardiac output, lower-limb blood flow and hepatic blood flow were within the normal range. Renal blood flow was significantly reduced. Lower-limb blood flow was negatively correlated with mean arterial pressure. 4. If borderline hypertension is an early stage of fixed hypertension, the present study suggests that the changes in cardiac output observed in hypertension are mainly related to lower-limb (and muscle) blood flow.

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