scholarly journals In situ hybridisation of a large repertoire of muscle-specific transcripts in fish larvae: the new superficial slow-twitch fibres exhibit characteristics of fast-twitch differentiation

2006 ◽  
Vol 209 (2) ◽  
pp. 372-379 ◽  
Author(s):  
F. Chauvigne
Keyword(s):  
Fish Larvae ◽  
In Situ Hybridisation ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Large Repertoire

ATP depletion in slow-twitch red muscle of rat

1987 ◽  
Vol 253 (3) ◽  
pp. C426-C432 ◽  
Author(s):  
D. M. Whitlock ◽  
R. L. Terjung
Keyword(s):  
Adenine Nucleotide ◽  
Atp Depletion ◽  
Cellular Events ◽  
Contraction Condition ◽  
Red Muscle ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

Rat slow-twitch muscle, in contrast to fast-twitch muscle, maintains its ATP content near normal during intense stimulation conditions that produce rapid fatigue. An extensive depletion of adenine nucleotide content by the deamination of AMP to IMP + NH3, typical of fast-twitch muscle, does not occur. We evaluated whether this response of slow-twitch muscle could be simply due to failure of synaptic transmission or related to cellular conditions influencing enzyme activity. Stimulation of soleus muscles in situ via the nerve or directly in the presence of curare at 120 tetani/min for 3 min resulted in extensive fatigue but normal ATP contents. Thus the lack of ATP depletion must be related to cellular events distal to neuromuscular transmission. Even nerve and direct muscle stimulation (with curare) during ischemia did not cause a large depletion of ATP or a large elevation of lactate content (12.0 +/- 0.7 mumol/g), even though the decline in tension was essentially complete. However, if the same tension decline during ischemia was prolonged by stimulating for 10 min at 12 tetani/min a large decrease in ATP (2.24 +/- 0.09 mumol/g) and increase in IMP (2.47 +/- 0.16 mumol/g) and lactate (30.4 +/- 2.0 mumol/g) content occurred. Thus adenine nucleotide deamination to IMP can occur in slow-twitch muscle during specific contraction conditions. The cellular events leading to the activation of AMP deaminase require an intense contraction condition and may be related to acidosis caused by a high lactate content.

Mechanical properties of muscle units in the cat diaphragm

1988 ◽  
Vol 59 (3) ◽  
pp. 1055-1066 ◽  
Author(s):  
M. Fournier ◽  
G. C. Sieck
Keyword(s):  
Contractile Properties ◽  
Fatigue Properties ◽  
Tetanic Force ◽  
Wide Range ◽  
The Mean ◽  
Slow Twitch ◽  
The Right ◽  
Fast Twitch ◽  
Tetanic Tension

1. Muscle units in the right sternocostal region of the cat diaphragm (DIA) were isolated in situ by dissecting filaments of the C5 ventral root. Isometric contractile and fatigue properties of DIA units were then measured. Contractile properties included: twitch contraction time (CT), peak twitch tension (Pt), maximum tetanic tension (P0), and the frequency dependence of tension production. Muscle-unit fatigue resistance was estimated using a 2-min fatigue test. 2. DIA muscle units were classified as fast (F) or slow (S) based on the presence or absence of sag in their unfused tetanic force responses. Muscle-unit fatigue indices (FI) were used to further classify DIA units as slow-twitch fatigue-resistant (S), fast-twitch fatigue-resistant (FR) fast-twitch fatigue-intermediate (FInt), or fast-twitch fatigable (FF) types. 3. Based on a total of 47 completely characterized DIA muscle units, 21% were classified as S, 4% as FR, 28% as FInt, and 47% as FF. In contrast to the distribution of unit types in other mixed appendicular muscles, the DIA was composed of a very low proportion of FR units and a relatively high proportion of FInt units. An interval of FIs between 0.50 and 0.75 separated units into fatigue-resistant and fatigable groups. The distribution of FIs for FF and most FInt units was continuous, indicating that they formed a single fatigable group. Relatively few FF units in the DIA had FIs less than 0.10. 4. A wide range of contractile properties was observed for DIA muscle units. Type S units had longer CTs and lower Pt and P0 values than type F units. The mean Pt and P0 of FF and FInt units were comparable, whereas the mean Pt and P0 of the two FR units were lower. Type S units produced a greater proportion of their P0 at lower frequencies of activation than type F units. The lower P0S produced by type F units in the DIA indicated that they were smaller than similar units in appendicular muscles. It was concluded that in meeting most normal ventilatory requirements, adequate force could be generated by the recruitment of only type S and FR units. The recruitment of the more fatigable FF and FInt units may occur only during more forceful respiratory and nonrespiratory behaviors of the DIA.

Influence of training on blood flow to different skeletal muscle fiber types

1983 ◽  
Vol 55 (4) ◽  
pp. 1072-1078 ◽  
Author(s):  
B. G. Mackie ◽  
R. L. Terjung
Keyword(s):  
Blood Flow ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Plantaris Muscle ◽  
Blood Flows ◽  
Energy Demands ◽  
Flow Capacity ◽  
Slow Twitch ◽  
Fast Twitch

Blood flows to fast-twitch red (FTR), fast-twitch white (FTW), and slow-twitch red (STR) fiber sections of the gastrocnemius-soleus-plantaris muscle group of sedentary and trained rats were determined using radiolabeled microspheres during the 1st and 10th min of in situ contractions at frequencies ranging from 7.5 to 90 tetani/min. Treadmill training increased the cytochrome c content of both FTW (6.0 +/- 0.13 nmol/g to 12.2 +/- 0.27) and FTR (22.2 +/- 0.32 to 26.7 +/- 0.25) muscle. Loss of tension, evident at 15 tetani/min and above, was less (P less than 0.001) in trained animals. Although steady-state blood flows (10th min) to FTR and STR fibers were not altered by training, initial flows (1st min) to the trained FTR section were greater (P less than 0.025). Overall initial flows to both red fiber types were excessively high at the easier contraction conditions, but subsequently declined to values more reflective of the expected energy demands. This time-dependent relative hyperemia was not found in either sedentary or trained FTW muscle. However, training increased the maximal blood flow in the FTW sections [60 +/- 3.2 (n = 36) vs. 88 +/- 5.2 ml X min X 100 g-1 (n = 36)]. This 40-50% increase in FTW blood flow would produce only a modest 10% increase in blood flow to a whole mixed-fiber muscle, since the flow capacity of the FTW muscle is only one third to one fourth that of FTR muscle. This overall increase in blood flow, however, is similar to changes in VO2max found in trained rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Tissue adenosine content in active soleus and gracilis muscles of cats

1983 ◽  
Vol 244 (4) ◽  
pp. H552-H559 ◽  
Author(s):  
E. L. Bockman ◽  
J. E. McKenzie
Keyword(s):  
Cardiac Muscle ◽  
Soleus Muscle ◽  
Gracilis Muscle ◽  
Fiber Types ◽  
Amp Deaminase ◽  
Vascular Conductance ◽  
Cast Doubt ◽  
Slow Twitch ◽  
Fast Twitch

Vascularly isolated cat soleus and gracilis muscles were stimulated to contract isometrically and were then frozen in situ. Adenosine, inosine, and hypoxanthine (nucleosides), and lactate were measured in neutralized, perchloric acid extracts of muscle. During contraction, nucleoside content increased in soleus muscle but changed little in gracilis muscle. However, adenosine content did not correlate with vascular conductance or oxygen consumption in either soleus or gracilis muscle. Adenosine content did correlate with lactate content in soleus but not gracilis muscle. The activity of AMP deaminase was highest in cat gracilis muscle and lowest in dog cardiac muscle. The activity of 5'-nucleotidase was lowest in cat gracilis muscle and highest in dog cardiac muscle. Cat soleus and dog gracilis muscles had intermediate activities of both enzymes. The findings of the present study do not support a role for adenosine in mediating prolonged active hyperemia in fast-twitch gracilis muscle of cats and cast doubt on such a role in slow-twitch soleus muscle of cats. Differences in the activities of AMP deaminase and 5'-nucleotidase provide a qualitative, biochemical explanation for apparent differences in net adenosine production among muscles composed of different fiber types and between skeletal and cardiac muscle.

Physiological characteristics of skeletal muscles of dogs and cats

1977 ◽  
Vol 233 (1) ◽  
pp. C14-C18 ◽  
Author(s):  
L. C. Maxwell ◽  
J. K. Barclay ◽  
D. E. Mohrman ◽  
J. A. Faulkner
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Skeletal Muscles ◽  
Physiological Characteristics ◽  
Maximum Oxygen Consumption ◽  
Biochemical Characteristics ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Succinate Oxidase

Our purpose was to determine if physiological characteristics of skeletal muscles of dogs and cats are related to their histochemical and biochemical characteristics. Maximum oxygen consumption (VO2max) and blood flow (Q) at VO2max were determined for in situ muscles of dogs and cats. Compared to cat muscles, dog muscles per unit mass had higher succinate oxidase activities, VO2max's, and Q's at VO2max's. There are positive relationships between Q at VO2max and VO2max and between VO2max and succinate oxidase activity. The higher VO2max's and succinate oxidase activities of dog muscles are consistent with the presence in these muscles of only slow-twitch fatique-resistant fibers and fast-twitch fatique-resistant fibers, whereas up to 50% of the fibers found in cat muscles are fast-twitch fatiqable. Capillary-to-fiber ratios are 2.40-2.97 for dog muscles compared to 2.17-2.84 for cat muscles. Thus the two- to threefold higher Q at VO2max for dog muscles compared to cat muscles is not due to a greater number of capillaries.

Differences in ammonia and adenylate metabolism in contracting fast and slow muscle

1979 ◽  
Vol 237 (3) ◽  
pp. C111-C118 ◽  
Author(s):  
R. A. Meyer ◽  
R. L. Terjung
Keyword(s):  
Time Course ◽  
Adenine Nucleotide ◽  
Ammonia Concentration ◽  
Slow Muscle ◽  
Tension Development ◽  
Fast And Slow Muscle ◽  
Slow Twitch ◽  
Muscle Changes ◽  
Fast Twitch

The time course of AMP deamination and IMP reamination was studied during in situ stimulation and subsequent recovery in fast-twitch (gastrocnemius) and slow-twitch (soleus) muscles of pentobarbital-anesthetized rats. Muscles were stimulated tetanically at rates that initially produced comparable decreases (40%) in tension development. In fast muscle, progressive decreases in total adenine nucleotide (TAN) contents of up to 50% were balanced by equivalent increases in IMP contents. Ammonia concentration initially increased in a 1:1 stoichiometry with changes in IMP and TAN. During recovery following stimulation, IMP removal matched, but NH3 removal exceeded the rate of TAN resynthesis. In contrast, TAN content in slow muscle was only slightly decreased (10%) during stimulation and there were no increases in IMP or NH3. Stimulation of the soleus following ligation of the blood supply did not increase TAN depletion. In both fast and slow muscle, changes in glutamate, aspartate, and alanine could be accounted for by transamination. These results illustrate a fundamental difference in adenylate metabolism during intense muscle stimulation between fast- and slow-twitch mammalian muscle.

Influence of thyroid status on skeletal muscle LPL activity and TG uptake

1980 ◽  
Vol 238 (6) ◽  
pp. E518-E523 ◽  
Author(s):  
H. Kaciuba-Uscilko ◽  
G. A. Dudley ◽  
R. L. Terjung
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Thyroid Status ◽  
Different Types ◽  
Slow Twitch ◽  
Fast Twitch ◽  
Fractional Uptake

The influence of thyroid status on the clearance of chylomicron 14C-labeled triglycerides (14C-TG), the fractional uptake of 14C-TG, and activity of lipoprotein lipase (LPL) in the different skeletal muscle fiber types was evaluated in pentobarbital-anesthetized rats. The turnover of plasma TG was approximately fourfold greater in the hyperthyroid (HyperT) compared to either euthyroid (EUT) or hypothyroid (HypoT) animals. The uptake of 14C-TG was increased in slow-twitch red and fast-twitch red muscle sections of the HyperT group and normal in the HypoT group. The changes in LPL activity in these two fiber types were inversely related to thyroid influence, with decreases found in the HyperT group and increases found in the HypoT group. Thus, the uptake of 14C-TG in these high-oxidative fibers, relative to the LPL activity, varied directly with thyroid influence. As a result, the normal linear relationship, apparent for the different types of skeletal muscle, between LPL activity measured in vitro and TG uptake determined in situ was not maintained.

Myosin light chain phosphorylation in fast and slow skeletal muscles in situ

1984 ◽  
Vol 247 (5) ◽  
pp. C462-C471 ◽  
Author(s):  
R. L. Moore ◽  
J. T. Stull
Keyword(s):  
Skeletal Muscle ◽  
Light Chain ◽  
Skeletal Muscles ◽  
Myosin Light Chain ◽  
White Muscle ◽  
Slow Muscle ◽  
Phosphate Content ◽  
Slow Twitch ◽  
Fast Twitch

The physiological properties of contraction-induced phosphate incorporation into the phosphorylatable light chain (P-light chain) of myosin were examined in fast-twitch white, fast-twitch red, and slow-twitch skeletal muscles in situ. Neural stimulation of rat gastrocnemius muscles between 0.5 and 100 Hz produced an increase in the phosphate content of the P-light chain from the white portion of the muscle, and the rate of P-light chain phosphorylation was frequency dependent. The extent of phosphorylation of P-light chain from the fast-twitch red portion of the gastrocnemius muscle was less. In contrast to fast-twitch skeletal muscle, only high-frequency stimulation (30-100 Hz) produced a small increase in the phosphate content of P-light chain from the slow-twitch soleus muscle. Fast white muscle contained 2.2 and 3.5 times more myosin light chain kinase activity than did the fast red and slow muscle, respectively. The rate of P-light chain dephosphorylation was four times faster in slow muscle than in fast white muscle. Thus the greater extent of phosphorylation of P-light chain in fast-twitch white skeletal muscle fibers may be due in part to the presence of more kinase and less phosphatase activities. Isometric twitch tension potentiation was correlated to the extent of phosphorylation of P-light chain from fast white muscle. The physiological consequences of P-light chain phosphorylation are likely to be of greatest importance in fast-twitch white muscle.

Bio-P and non-bio-P bacteria identification by a novel microbial approach

1999 ◽  
Vol 39 (6) ◽  
pp. 13-20 ◽  
Author(s):  
Philip L. Bond ◽  
Jürg Keller ◽  
Linda L. Blackall
Keyword(s):  
In Situ Hybridisation ◽  
Microbial Populations ◽  
Biological Phosphorus Removal ◽  
Gram Positive Bacteria ◽  
P Content ◽  
Identification Of Bacteria ◽  
Widespread Belief ◽  
Biological Phosphorus ◽  
P Removal

Culturing bacteria from activated sludge with enhanced biological phosphorus removal (EBPR) has strongly implicated Acinetobacter with the process. However, using fluorescent in-situ hybridisation (FISH) probing to analyse microbial populations, we have shown evidence opposing this widespread belief. We describe the phosphorus (P) removing performance and microbial population analyses of sludges obtained in a laboratory scale EBPR reactor. Two sludges with extremely high P removing capabilities were examined, the P content of these sludges was 8.6% (P sludge) and 12.3% (S sludge) of the MLSS. Identification of bacteria using FISH probing indicated both sludges were dominated by microbes from the beta proteobacteria and high mol% G+C Gram positive bacteria. Acinetobacter could make up only a small proportion of the cells in these sludges. Sludge with extremely poor P removal (P content of 1.5%, referred to as T sludge) was then generated by reducing the P in the influent. Bacteria resembling the G-bacteria became abundant in this sludge and these were identified using FISH probing. The anaerobic transformations of the T and P sludges correlated well with that of the non-EBPR and EBPR biological models respectively, indicating that bacteria in the T sludge have the potential to inhibit P removal in EBPR systems.

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