Relative metabolic utilization of in situ rabbit soleus muscle: thermistor-based measurements and model

2000 ◽  
Vol 203 (23) ◽  
pp. 3667-3674
Author(s):  
K.J. Gustafson ◽  
G.D. Egrie ◽  
S.H. Reichenbach

Electrically conditioned skeletal muscle can provide the continuous power source for cardiac assistance devices. Optimization of the available sustained power from in vivo skeletal muscle requires knowledge of its metabolic utilization and constraints. A thermistor-based technique has been developed to measure temperature changes and to provide a relative estimate for metabolic utilization of in situ rabbit soleus muscle. The relative thermistor response, active tension and muscle displacement were measured during cyclic isometric and isotonic contractions across a range of muscle tensions and contraction durations. The thermistor response demonstrated linear relationships versus both contraction duration at a fixed muscle length and active tension at a fixed contraction duration (r(2)=0.90+/−0.14 and 0.70+/−0.21, respectively; means +/− s.d.). A multiple linear regression model was developed to predict normalized thermistor response, DeltaT, across a range of conditions. Significant model variables were identified using a backward stepwise regression procedure. The relationships for the in situ muscles were qualitatively similar to those reported for mammalian in vitro muscle fiber preparations. The model had the form DeltaT=C+at(c)F+bW, where the constant C, and coefficients for the contraction duration t(c) (ms), normalized active tension F and normalized net work W were C=−1.00 (P<0.001), a=5.97 (P<0.001) and b=2.12 (P<0.001).

2005 ◽  
Vol 289 (6) ◽  
pp. R1770-R1776 ◽  
Author(s):  
David P. Basile ◽  
Deborah L. Donohoe ◽  
Shane A. Phillips ◽  
Jefferson C. Frisbee

In addition to the long-term renal complications, previous studies suggested that after acute renal failure (ARF), rats manifest an increased pressor response to an overnight infusion of ANG II. The present study tested whether recovery from ARF results in alterations in sensitivity to the peripheral vasculature. ARF was induced in Sprague-Dawley rats by 45 min of bilateral renal ischemia and reperfusion. Animals were allowed to recover renal structure and function for 5–8 wk, after which the acute pressor responses to ANG II were evaluated either in vivo in in situ skeletal muscle arterioles or in isolated gracilis muscle arteries in vitro. Baseline arterial pressure was not different in ARF rats vs. sham-operated controls, although ARF rats exhibited an enhanced pressor response to bolus ANG II infusion compared with control rats. Steady-state plasma ANG II concentration and plasma renin activity were similar between ARF and control rats. Constrictor reactivity of in situ cremasteric arterioles from ARF rats was enhanced in response to increasing concentrations of ANG II; however, no difference was observed in arteriolar responses to elevated Po2, norepinephrine, acetylcholine, or sodium nitroprusside. Isolated gracilis muscle arteries from ARF rats also showed increased vasoconstriction in response to ANG II but not norepinephrine. In conclusion, recovery from ischemic ARF is not associated with hypertension but is associated with increased arteriolar constrictor reactivity to ANG II. Although the mechanisms of this altered responsiveness are unclear, such changes may relate, in part, to cardiovascular complications in patients with ARF and/or after renal transplant.


2015 ◽  
Vol 9 (1) ◽  
pp. 262-269 ◽  
Author(s):  
K. Strohschein ◽  
P Radojewski ◽  
T. Winkler ◽  
G.N. Duda ◽  
C Perka ◽  
...  

Cell-based therapies have emerged during the last decade in various clinical fields. Especially mesenchymal stromal cells (MSCs) have been used in pre-clinical and clinical applications in cardiovascular, neurodegenerative and musculoskeletal disorders. In order to validate survival and viability as well as possible engraftment of MSCs into the host tissue a live cell imaging technique is needed that allows non-invasive, temporal imaging of cellular kinetics as well as evaluation of cell viability after transplantation. In this study we used luciferase-based bioluminescence imaging (BLI) to investigate the survival of autologous MSCs transplanted into a severely crushed soleus muscle of the rats. Furthermore we compared local as well as intra-arterial (i.a.) administration of cells and analyzed if luciferase transduced MSCs depict the same characteristics in vitro as non-transduced MSCs. We could show that transduction of MSCs does not alter their in vitro characteristics, thus, transduced MSCs display the same differentiation, proliferation and migration capacity as non-transduced cells. Using BLI we could track MSCs transplanted into a crushed soleus muscle until day 7 irrespective of local or i.a. application. Hence, our study proves that luciferase-based BLI is a suitable method for in vivo tracking of MSCs in skeletal muscle trauma in rats.


1993 ◽  
Vol 265 (5) ◽  
pp. E736-E742 ◽  
Author(s):  
K. S. Chen ◽  
J. C. Friel ◽  
N. B. Ruderman

The presence of phosphatidylinositol 3-kinase (PI 3-kinase) in mammalian skeletal muscle and its response to insulin stimulation were investigated. PI kinase, immunoprecipitated from rat soleus muscle with antibodies directed toward its 85-kDa subunit phosphorylated PI, phosphatidylinositol 4-phosphate [PI(4)P], and phosphatidylinositol 4,5,-bisphosphate [PI(4,5)P2] to yield phosphatidylinositol 3-phosphate [PI(3)P], phosphatidylinositol 3,4,-bisphosphate, and phosphatidylinositol trisphosphate in vitro. PI 3-kinase activity was also immunoprecipitated with antiphosphotyrosine [alpha-Tyr(P)] antibodies and with antibodies raised against IRS-1, a substrate of the insulin receptor protein tyrosine kinase that associates with and activates PI 3-kinase. Incubation of the soleus with insulin in vitro, or injection of insulin into rats in vivo, produced three- to fivefold increases in alpha-Tyr(P)- and alpha-IRS-1-immunoprecipitable PI 3-kinase activity. In nonstimulated soleus muscle, PI 3-kinase activity immunoprecipitated with alpha-IRS-1 or with alpha-Tyr(P) antibodies was evenly distributed between particulate (200,000-g pellet) and soluble fractions. Insulin treatment increased immunoprecipitable PI 5-kinase activity in both fractions, but the increase in alpha-Tyr-(P)-precipitable activity was greater in the particulate fraction, whereas the increase in alpha-IRS-1-precipitable activity was greater in the soluble fraction. In intact soleus muscles incubated with 32PO4, insulin increased the labeling of PI(3)P but did not affect the labeling of PI(4)P or PI(4,5)P2. Activation of PI 3-kinase by insulin was unaffected by prior denervation of the muscle, a manipulation that has been shown to cause both insulin resistance and hypersensitivity in muscles, depending on the parameter measured.(ABSTRACT TRUNCATED AT 250 WORDS)


1987 ◽  
Vol 244 (3) ◽  
pp. 655-660 ◽  
Author(s):  
L Budohoski ◽  
R A Challiss ◽  
A Dubaniewicz ◽  
H Kaciuba-Usciłko ◽  
B Leighton ◽  
...  

1. Prolonged elevation of the plasma adrenaline concentration was produced in rats by implantation of adrenaline-releasing retard-tablets. With this technique, a hyperadrenalinaemic state is maintained for at least 5 days. 2. At 6 h after implantation of the retard-tablet it was found that plasma glucose and fatty acid concentrations increased and insulin concentration decreased compared with values obtained from placebo-tablet-implanted rats. Administration of a subcutaneous glucose load demonstrated an impaired glucose tolerance in vivo, and incubation of soleus muscle strips from 6 h-hyperadrenalinaemic rats in vitro demonstrated a decreased sensitivity of the rates of glycolysis and glucose transport to insulin. 3. The sensitivities of the rates of glycolysis, glucose transport and glycogen synthesis to insulin were determined for the incubated soleus muscle preparation isolated from animals after 48 h, 72 h and 120 h duration of hyperadrenalinaemia. At 48 h after retard-tablet implantation, the sensitivity of the processes of glucose transport and glycolysis was decreased; at 72 h, the insulin-sensitivities of the rates of glycolysis and glucose transport in skeletal muscle were similar to those determined for control animals; at 120 h, however, the sensitivities of the processes of glucose transport and glycolysis were both statistically significantly increased. In contrast, no changes in the sensitivity of the process of glycogen synthesis were observed at any of the time intervals studied. 4. The possible biochemical basis for the observed changes in skeletal-muscle insulin-sensitivity with prolonged hyperadrenalinaemia is discussed.


1985 ◽  
Vol 58 (2) ◽  
pp. 521-527 ◽  
Author(s):  
P. A. Deuster ◽  
E. L. Bockman ◽  
S. M. Muldoon

Strips of soleus (100% type I) and gracilis (90% type II) muscle were obtained from anesthetized cats and mounted in organ baths filled with aerated Krebs-Ringer solution (37 degrees C). The contractile patterns in response to electrical stimulation (0.1 Hz, 25 V, 5 ms), caffeine, halothane, and caffeine in the presence of halothane were examined in the two fiber types. The ability of 25 microM dantrolene to alter the contractile patterns was also evaluated. In vitro contractile properties in response to electrical stimulation were similar to properties observed in situ, except that twitch tension in soleus muscle was significantly less in vitro than in situ. In the presence of halothane, type I soleus muscle developed a rapid contracture. The contracture was blocked by pretreatment with dantrolene and was reversed by addition of dantrolene at the peak of the response. Halothane-induced contractures were not observed at any time in type II gracilis. Type I soleus was also significantly more sensitive both to caffeine alone and to caffeine in the presence of halothane than was type II gracilis. In both fiber types, halothane increased the sensitivity of the muscles to caffeine. Dantrolene attenuated caffeine-induced contractures in both fiber types, but the attenuating effect was less in the presence of halothane. The findings of a halothane-induced contracture in the cat soleus and differential sensitivities of the two muscle fiber types to caffeine indicate that further studies in these two muscles may be useful for delineating the mechanisms inducing contracture in muscle from individuals susceptible to malignant hyperthermia.


1991 ◽  
Vol 274 (1) ◽  
pp. 187-192 ◽  
Author(s):  
B Leighton ◽  
M Parry-Billings ◽  
G Dimitriadis ◽  
J Bond ◽  
E A Newsholme ◽  
...  

This study examined the effects of antagonism of the peak level of glucocorticoids in vivo, which occurs as rats enter the feeding/activity (dark) period on glucose and glutamine metabolism in incubated isolated rat soleus muscle preparations. Thus the rats were treated with the potent glucocorticoid antagonist RU 486 2 h before and 1 and 2 h into the dark period. Both the content of glutamine in skeletal muscle in vivo and plasma glucose and glutamine concentrations were elevated midway through the dark period, compared with the beginning of the period. RU 486 prevented the increases in plasma glucose and glutamine and caused a significant decrease in both the rate of release of glutamine in soleus muscle in vitro and the content of glutamine in gastrocnemius muscle. The sensitivity of soleus muscle to insulin in vitro is markedly decreased when isolated midway through the dark period (i.e. at 03:00 h) [Leighton, Kowalchuk, Challiss & Newsholme (1988) Am. J. Physiol. 255, E41-E45]. We now show that the concentrations of insulin required to stimulate lactate formation and glycogen synthesis half-maximally were 95 and 250 muunits/ml respectively, and treatment of rats with RU 486 decreased these values to 55 and 90 muunits of insulin/ml respectively. Thus antagonism of the action of the normal circadian rise in the level of glucocorticoids in rats reverses insulin insensitivity in soleus muscles in vitro.


1992 ◽  
Vol 263 (2) ◽  
pp. C287-C293 ◽  
Author(s):  
K. W. Rundell ◽  
P. C. Tullson ◽  
R. L. Terjung

AMP deaminase, which hydrolyses AMP to inosine 5'-monophosphate (IMP) and NH3 at high rates during excessive energy demands in skeletal muscle, is activated when bound to myosin in vitro. We evaluated AMP deaminase binding in vivo during muscle contractions to assess whether binding 1) is inherent to deamination and found only with high rates of IMP production or simply coincident with the contractile process and 2) requires cellular acidosis. AMP deaminase activity (mumol.min-1.g-1) was measured in the supernatant (free) and 10(4)-g pellet (bound) homogenate fractions of muscle of anesthetized rats after in situ contractions to determine the percent bound. In resting muscle, nearly all (approximately 90%) AMP deaminase is free (cytosolic). During contractions when energy balance was well maintained, binding did not significantly differ from resting values. However, during intense contraction conditions that lead to increased IMP concentration, binding increased to approximately 60% (P less than 0.001) in fast-twitch and approximately 50% in slow-twitch muscle. Binding increased in an apparent first-order manner and preceded initiation of IMP formation. Further, binding rapidly declined within 1 min after cessation of intense stimulation, even though the cell remained extremely acidotic. Extensive binding during contractions was also evident without cellular acidosis (iodoacetic acid-treated muscle). Thus the in vivo AMP deaminase-myosin complex association/dissociation is not coupled to changes in cellular acidosis. Interestingly, binding remained elevated after contractions, if energy recovery was limited by ischemia. Our results are consistent with myosin binding having a role in AMP deaminase activation and subsequent IMP formation in contracting muscle.


2001 ◽  
Vol 155 (3) ◽  
pp. 381-392 ◽  
Author(s):  
Jacquelyn Gerhart ◽  
Brian Bast ◽  
Christine Neely ◽  
Stephanie Iem ◽  
Paula Amegbe ◽  
...  

The epiblast of the chick embryo gives rise to the ectoderm, mesoderm, and endoderm during gastrulation. Previous studies revealed that MyoD-positive cells were present throughout the epiblast, suggesting that skeletal muscle precursors would become incorporated into all three germ layers. The focus of the present study was to examine a variety of organs from the chicken fetus for the presence of myogenic cells. RT-PCR and in situ hybridizations demonstrated that MyoD-positive cells were present in the brain, lung, intestine, kidney, spleen, heart, and liver. When these organs were dissociated and placed in culture, a subpopulation of cells differentiated into skeletal muscle. The G8 antibody was used to label those cells that expressed MyoD in vivo and to follow their fate in vitro. Most, if not all, of the muscle that formed in culture arose from cells that expressed MyoD and G8 in vivo. Practically all of the G8-positive cells from the intestine differentiated after purification by FACS®. This population of ectopically located cells appears to be distinct from multipotential stem cells and myofibroblasts. They closely resemble quiescent, stably programmed skeletal myoblasts with the capacity to differentiate when placed in a permissive environment.


1999 ◽  
Vol 277 (3) ◽  
pp. R917-R921 ◽  
Author(s):  
Benoît M. Lapointe ◽  
Claude H. Côté

Anesthetic agents can interfere with measurement of skeletal muscle contractility in vivo or in situ. Data obtained in vitro are however believed to be unaffected by such drugs. Our objective was to compare in vitro contractile measurements of fast- and slow-twitch muscles dissected from rats anesthetized with pentobarbital sodium (PS, 50 mg/kg ip) or with a mixture of ketamine and xylazine (KX, 87.5:12.5 mg/kg ip). The soleus (Sol) and extensor digitorum longus (EDL) muscles were precisely dissected 10 and 20 min after induction of anesthesia and equilibrated for 20 min in vitro before measuring contractile properties. All data obtained from PS rats were comparable with published values obtained under similar conditions. In EDL, maximum tetanic tension (Po) in KX rats was significantly decreased at both times compared with that in PS muscles. In the Sol, only the muscles exposed for 20 min to KX showed a decreased Po. These results clearly emphasize the need for investigators assessing skeletal muscle contractility in vitro to take into account the type of anesthetics used and the time of in vivo exposition to the drug.


Endocrinology ◽  
2010 ◽  
Vol 151 (10) ◽  
pp. 4696-4704 ◽  
Author(s):  
Steven T. Russell ◽  
Michael J. Tisdale

The mechanism by which the adipokine zinc-α2-glycoprotein (ZAG) increases the mass of gastrocnemius, but not soleus muscle of diabetic mice, has been evaluated both in vivo and in vitro. There was an increased phosphorylation of both double-stranded RNA-dependent protein kinase and its substrate, eukaryotic initiation factor-2α, which was attenuated by about two-thirds in gastrocnemius but not soleus muscle of ob/ob mice treated with ZAG (50 μg, iv daily) for 5 d. ZAG also reduced the expression of the phospho forms of p38MAPK and phospholipase A2, as well as expression of the ubiquitin ligases (E3) muscle atrophy F-box/atrogin-1 and muscle RING finger protein, and the increased activity of both caspase-3 and casapse-8 to values found in nonobese controls. ZAG also increased the levels of phospho serine-threonine kinase and mammalian target of rapamycin in gastrocnemius muscle and reduced the phosphorylation of insulin receptor substrate-1 (Ser307) associated with insulin resistance. Similar changes were seen with ZAG when murine myotubes were incubated with high glucose concentrations (10 and 25 mm), showing that the effect of ZAG was direct. ZAG produced an increase in cAMP in murine myotubes, and the effects of ZAG on protein synthesis and degradation in vitro could be replicated by dibutyryl cAMP. ZAG increased cAMP levels of gastrocnemius but not soleus muscle. These results suggest that protein accretion in skeletal muscle in response to ZAG may be due to changes in intracellular cAMP and also that ZAG may have a therapeutic application in the treatment of muscle wasting conditions.


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