Effect of corticosterone on protein degradation in isolated rat soleus and extensor digitorum longus muscles

1996 ◽  
Vol 148 (3) ◽  
pp. 501-507 ◽  
Author(s):  
S B Bowes ◽  
N C Jackson ◽  
D Papachristodoulou ◽  
A M Umpleby ◽  
P H Sönksen
Keyword(s):  
Soleus Muscle ◽  
Extensor Digitorum Longus ◽  
Acute Effect ◽  
Term Treatment ◽  
Extensor Digitorum ◽  
Protein Breakdown ◽  
Significant Difference ◽  
Corticosterone Treatment ◽  
Edl Muscle ◽  
And Control

Abstract The net catabolic effect of glucocorticoids on protein metabolism is well documented but the acute and chronic effect of glucocorticoids on protein breakdown remains controversial. In the present studies protein breakdown was measured by the release of tyrosine from the isolated soleus and extensor digitorum longus (EDL) muscles of control rats and rats treated with corticosterone (10 mg/100 g body weight/day) for 5 days. The effect of corticosterone in arresting growth was confirmed since corticosterone-treated rats weighed significantly less than control rats after 2, 3, 4 and 5 days of treatment (P<0·001). Furthermore, the weights of soleus and EDL muscles from corticosterone-treated rats were significantly reduced (P<0·001, at least P<0·05 respectively) compared with muscles from control rats on days 3–5. In the EDL muscle tyrosine release was significantly elevated after corticosterone treatment for 2 days (257 ± 21 nmol/g tissue/h, P<0·05), 3 days (205 ± 9 nmol/g tissue/h, P<0·01), 4 days (255 ± 20 nmol/g tissue/h, P<0·005) and 5 days (218 ± 8 nmol/g tissue/h, P<0·05) compared with EDL from control rats (192 ± 13, 171 ± 7, 187 ± 7, 180 ± 12 nmol/g tissue/h respectively). In the soleus muscle, tyrosine release was significantly elevated after corticosterone treatment for 2 days (226 ± 14 nmol/g tissue/h, P<0·001), 3 days (223 ± 16 nmol/g tissue/h, P<0·001) and 4 days (199 ± 10 nmol/g tissue/h, P<0·001) compared with control rats (158 ± 7, 132 ± 6 and 153 ± 7 nmol/g tissue/h respectively). After 5 days there was no significant difference in tyrosine release from soleus muscle between corticosterone-treated (176 ± 15 nmol/g tissue/h) and control rats (157 ± 6 nmol/g tissue/h). Plasma glucose concentrations were not significantly different in rats treated with corticosterone and control rats whilst insulin levels were significantly raised in the corticosterone-treated rats on all days compared with control rats (P<0·05 on day 1; P<0·001 on days 2, 3, 4 and 5). It is suggested that insulin may have prevented hyperglycaemia developing in the corticosterone-treated rats. Results from these studies indicate that the acute effect of glucocorticoids is to increase muscle proteolysis but this is not maintained with longer-term treatment. Journal of Endocrinology (1996) 148, 501–507

scholarly journals Activity of mu- and m-calpain in regenerating fast and slow twitch skeletal muscles.

1996 ◽  
Vol 43 (4) ◽  
pp. 693-700 ◽  
Author(s):  
J Moraczewski ◽  
E Piekarska ◽  
M Zimowska ◽  
M Sobolewska
Keyword(s):  
Intracellular Calcium ◽  
Soleus Muscle ◽  
Muscle Regeneration ◽  
Skeletal Muscles ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Slow Twitch ◽  
Edl Muscle ◽  
Calpain Ii ◽  
Complete Regeneration

Calpains--non-lysosomal intracellular calcium-activated neutral proteinases, form a family consisting of several distinct members. Two of the isoenzymes: mu (calpain I) and m (calpain II) responded differently to the injury during complete regeneration of Extensor digitorum longus (EDL) muscle and partial regeneration of Soleus muscle. In the crushed EDL the level of m-calpain on the 3rd and 7th day of regeneration was higher than in non-operated muscles, whereas the activity of this calpain in injured Soleus decreased. The level of mu-calpain in EDL oscillated irregularly during regeneration whereas in Soleus of both injured and contralateral muscles its level rapidly rose. Our results support the hypothesis that m-calpain is involved in the process of fusion of myogenic cells whereas mu-calpain plays a significant but indirect role in muscle regeneration.

Properties of motor units in nerve-intact autografts of cat extensor digitorum longus muscles

1989 ◽  
Vol 62 (1) ◽  
pp. 231-238 ◽  
Author(s):  
T. G. Sandercock ◽  
C. Cote ◽  
J. A. Faulkner
Keyword(s):  
Extensor Digitorum Longus ◽  
Motor Units ◽  
Extensor Digitorum ◽  
Fatigue Properties ◽  
Specific Force ◽  
Mean Values ◽  
Control Value ◽  
Time To Peak ◽  
Significant Difference ◽  
Edl Muscle

1. In cats, isometric contractile properties were measured on five extensor digitorum longus (EDL) muscles and four EDL muscle grafts 150-270 days after autografting with nerves intact. Comparisons were made between the properties of whole muscles and grafts and between 36 motor units in control EDL muscles and 41 motor units in grafts. 2. The time-to-peak twitch force (TPT) of 23 +/- 1.7 (SE) ms for grafts was significantly prolonged compared with the value of 17 +/- 0.7 ms observed for whole EDL muscles. The mean values for the TPT of motor units were not different from the respective values for whole grafts or for whole muscles. The maximum specific force of whole grafts of 19.7 +/- 0.6 (SE) N/cm2 was significantly less than the control value of 23.6 +/- 0.6 N/cm2, an observation consistent with all previous data on the maximum specific force of grafts and control muscles. 3. Based on the presence or absence of sag and an index of fatigue, motor units were classified as fast fatigable (FF), fast intermediate (FI), fast fatigue-resistant (FR), and slow (S). Motor units were classified 33% FF, 22% FI, 27% FR, and 17% S in control muscles and 17% FF, 43% FI, 29% FR, and 12% S in autografted muscles. Compared with control muscles, the number of small FF units increased significantly in the autografts, but no significant difference was observed in the fatigue properties of motor units.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of carbonic anhydrases in type I muscle fibers influences contractility

1989 ◽  
Vol 67 (6) ◽  
pp. 645-649 ◽  
Author(s):  
C. Côté ◽  
D. Tremblay ◽  
H. Riverin ◽  
P. Frémont ◽  
P. A. Rogers
Keyword(s):  
Relaxation Time ◽  
Carbonic Anhydrase ◽  
Soleus Muscle ◽  
Extensor Digitorum Longus ◽  
Specific Inhibitor ◽  
Contractile Properties ◽  
Extensor Digitorum ◽  
Female Rats ◽  
Type I ◽  
Significant Difference

We tested the effects of inhibiting the carbonic anhydrase activity of rat soleus and extensor digitorum longus muscles on the isometric contractile properties and the resistance to fatigue. SOL and EDL muscles from female rats were incubated in vitro in the presence of methazolamide, a specific inhibitor of carbonic anhydrase, before determining their contractile properties. Methazolamide had no effects on the contractile properties of the soleus muscle (10−5 or 10−3 M) and extensor digitorum longus (10−3 M), except for the half-relaxation time of the soleus muscle which increased significantly. Values for half-relaxation time were significantly increased with both concentrations of the inhibitor. Muscles were then submitted to a fatigue protocol lasting 30 min. During the fatigue test, no significant difference was observed between control and 10−5 M methazolamide soleus muscles. In presence of 10−3 M methazolamide however, the soleus muscle showed a significantly increased resistance to fatigue compared with control preparations. No significant effect was observed with the extensor digitorum longus muscle exposed to 10−3 M methazolamide. Results are discussed in terms of the presence of two different isoforms of carbonic anhydrase that may be associated with calcium uptake and energy metabolic processes, respectively.Key words: carbonic anhydrase, skeletal muscle, contraction, fatigue, soleus muscle.

scholarly journals The acute effect of high intensity aerobic training on ANP and Endothelin-1 in obese women

2017 ◽  
Vol 6 (1) ◽  
pp. 49-54
Author(s):  
Rouhollah Haghshenas ◽  
Samaneh Nazemian ◽  
Mohsen Ebrahimi
Keyword(s):  
High Intensity ◽  
Aerobic Training ◽  
Acute Effect ◽  
Obese Women ◽  
Obese People ◽  
Endothelin 1 ◽  
Beneficial Effects ◽  
Significant Difference ◽  
Before And After ◽  
And Control

The purpose of this study was to investigate the effect of acute high intensity aerobic training on ANP and Endothelin-1 in inactive obese women. In order to nineteen obese women mean age± SD: 27.94± 3.30, mean weight ±SD: 88.13 ±7.28, mean height ±SD: 163.00± 4.91, mean BMI ±SD: 32.96± 3.13 selected and were randomly allocated to experimental and control groups. Experimental group performed a session acute aerobic exercise on ergometer at intensity 25w that increased every two minute 25w to workload and performed to exhaustion every subject. Samples blood were taken after 12 hours fasting, before and after of program training. For analyzed of biochemical variables used ELISA method and for analyses data used ANOVA. Results of this study showed that acute aerobic training causes significant increase in level of plasma ANP in obese women (p=0.006). But no significant differences observe in plasma level of Endothelin-1. Also, any significant difference didn’t observe between pre and post-training values, were separately compared data in each group. Finally, according to results of this study, acute aerobic training causes of the direct relationship between obesity and hypertension and cardiovascular disease probably beneficial effects of physical activity in obese people is due to change in these indicators.

Histochemical fiber type distribution and epinephrine sensitivity in normal and cross-transplanted rat muscles

1987 ◽  
Vol 65 (6) ◽  
pp. 1205-1212 ◽  
Author(s):  
John M. Kennedy ◽  
Franz S. F. Mong ◽  
James L. Poland
Keyword(s):  
Soleus Muscle ◽  
Extensor Digitorum Longus ◽  
Fiber Type ◽  
Extensor Digitorum ◽  
Glycogen Depletion ◽  
Type Distribution ◽  
Control Muscle ◽  
Glycogen Concentration ◽  
Fiber Type Distribution ◽  
Epinephrine Dose

The metabolic integrity of fully regenerated transplants was investigated by measuring induced changes in glycogen concentration. The extensor digitorum longus and the soleus muscles were cross transplanted: the extensor digitorum longus into the soleus muscle bed (SOLT) and the soleus muscle into the extensor digitorum longus bed (EDLT). The histochemical fiber type distribution of the regenerated muscles was determined and was found to transform in cross-transplanted EDLT and SOLT. After transplantation and regeneration, both muscles had initially low glycogen concentrations. However, the EDLT glycogen concentration was not significantly different from that of the contralateral extensor digitoium longus control muscle after 60 days. In the SOLT, glycogen gradually increased but remained less than in the contralateral soleus control muscle. SOLT and control soleus muscles responded with a significant glycogen depletion to an epinephrine dose two orders of magnitude less than the lowest dose affecting glycogen levels in EDLT and extensor digitorum longus muscles. These results indicate that transplanted muscles are capable of regenerating normal glycogenolytic responses and that the sensitivity of the response observed depends on the site of transplantation and is related to the type of innervation and histochemical fiber type.

Potentiation of the halothane-cooling contractures of mammalian muscles by denervation

1990 ◽  
Vol 68 (9) ◽  
pp. 1207-1213 ◽  
Author(s):  
Margarete M. Trachez ◽  
R. Takashi Sudo ◽  
G. Suarez-Kurtz
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Soleus Muscle ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Tension Development ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Denervated Muscles

Denervation potentiated the cooling-induced contractures and the halothane-cooling contractures of isolated extensor digitorum longus and soleus muscles of the mouse. These effects were more striking in extensor digitorum longus than in soleus muscles. Significant increases in the peak amplitudes of the halothane-cooling contractures of both muscles and of the cooling contractures of soleus muscle were observed within 2 and 7 days of denervation. The potentiation of the contractures persisted for 90 days, the period of this study. Denervation (>2 days) endowed extensor digitorum longus with the ability to generate cooling contractures in the absence of halothane. The rate of tension development of cooling-induced contractures in the absence or presence of halothane was significantly greater in denervated (2–90 days) than in innervated muscles. Denervation also reduced the effectiveness of procaine in inhibiting the halothane-cooling contractures. It is proposed that the potentiation of cooling-induced contractures in denervated muscles results primarily from an increase in the rate of efflux and in the quantity of Ca2+ released from the sarcoplasmic reticulum, upon cooling and (or) when challenged with halothane.Key words: denervation, excitation–contraction coupling, halothane, cooling-induced contractures, skeletal muscle.

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