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Biomedical subjects

C Bastien

Publications and source records attributed to C Bastien.

26 records · Page 2Linked to original sources
PubMed1984

Phosphagens and glycogen content in skeletal muscle after treadmill training in young and old rats.

The concentration of creatine phosphate (CrP), ATP, ADP, AMP and glycogen were measured in extensor digitorum longus (EDL) and in quadriceps muscles of 3, 6, 24, and 27 months old male Wistar rats groups. Young (3 months) and old (24 months) rats were trained for 12 weeks, 3 days a week, with running exercise session. Each training session was of 2 h. In sedentary groups and for both muscles, CrP, ATP, ADP, and glycogen contents decrease with aging (between 6 and 27 months). In spite of an AMP increase, total adenosine nucleotides (TAN) decrease significantly between 6-27 months (P less than 0.01) from 6.11 to 5.11 (EDL) and from 5.59 to 4.65 (quadriceps) mumol X g-1 wet weight muscle. After 12 weeks of physical training, the mean values of CrP, TAN, and glycogen were improved in both young and old rat groups. Moreover, the ATP/ADP ratios and the energy charge of the adenylate system were unrelated to age, but training decreases significantly the mean value of energy charge in both young and old groups. These results suggest that, as far as energy-rich phosphagen metabolism is concerned young and old muscles show the same pattern response to training.

Adenine Nucleotides↗
PubMed1983

Enzymatic adaptations to treadmill training in skeletal muscle of young and old rats.

The activities of lactic dehydrogenase (LDH), hexokinase (HK), citrate synthetase (CS), and 3-hydroacyl CoA dehydrogenase (HAD), were measured in Soleus and extensor digitorum longus (EDL) muscles of four different age groups of male Wistar rats. Young rats (3 months) and old rats (24 months) were trained during 12 weeks by a 3 days a week running exercises session. Each training session was of 2 h. All the enzymatic activities increased between 3 and 6 months in both Soleus and EDL muscles. During aging (6-27 months) Soleus showed about the same percent decrease in enzymatic activities (30%) for the four enzymes studied. In contrast with Soleus, CS activity of EDL increased with age but HK, LDH, and HAD decreased. The training induced an improvement of all enzymatic activities, except for LDH, which decreased with training in same cases. In the old group the training effect was more important than in the young group. When the relative enzymatic activities were compared it was found that Soleus muscle keeps its energy supply enzyme pattern during aging, whereas EDL evolutes to a more oxidative metabolism. Moreover old skeletal muscle remains trainable and training induces an enzymatic adaptation which follows the same pattern in both muscles: an increase of HK, CS, and HAD activities and a decrease of LDH.

Aging↗
PubMed1979

[Cytochrome P-450 and transformation from 18-hydroxycorticosterone to aldosterone].

The authors have studied the in vitro conversion of 18 hydroxycorticostérone to aldosterone (18 oxidation) by duck adrenal subcellular fractions. Considering the new hypothesis about the mechanism of this step (hydroxylation mechanism) the authors have investigated a possible relationship between this reaction and cytochrome P450. With experimental conditions described, data show that metyrapone, a cytochrome P450 competitive inhibitor does not inhibit 18 oxidation. In contrast, 18 oxidation is inhibited by spirolactones (spironolactones, canrenone, potassium canrenoate). These compounds act at the cytochrome P450 level but have also an uncoupling effect which has been recently discovered. The effects of metyrapone and spirolactones on 18 oxidation as well as the different behaviour between biologicaly and organically synthetised 18 hydroxycorticosterone allow us to propose hypotheses for the mechanism of this step.

18-Hydroxycorticosterone↗
PubMedDate not supplied

Metabolic enzymatic activities in the diaphragm of normal men and patients with moderate chronic obstructive pulmonary disease.

The activities of hexokinase (HK), lactate dehydrogenase (LDH), citrate synthase (CS) and 3-hydroxyacyl-CoA-dehydrogenase (HAD) were measured in the costal diaphragm (DI) and in the latissimus dorsi (LD), a non respiratory muscle, of 21 middle aged men: 10 normal subjects and 11 patients with moderate chronic obstructive pulmonary disease (COPD). In the normal subjects, all the enzymatic activities were significantly higher in the diaphragm (p less than 0.01) than in the latissimus dorsi, the mean increase ranging from 61 to 118%. Chronic obstructive pulmonary disease failed to cause any further increase in enzymatic activities in the DI; on the contrary, a significant decrease of HK and LDH (30%, p less than 0.01) was observed. Enzymatic activities of LD were unaffected by COPD. These data show that the metabolic enzymatic activities in the diaphragm of normal middle aged subjects is similar to that of the vastus lateralis of highly trained young athletes, suggesting that DI is a highly trained muscle in normal man.

3-Hydroxyacyl CoA Dehydrogenases↗