ABSTRACT
This paper reports on an experiment concerning the involvement of catecholamines in the biosynthesis of nucleic acids and proteins at muscular levels, using various types of skeletal muscles (psoas, diaphragm, soleus) and heart muscles from male Wistar rats treated with adrenalin. Assessment of the biosynthetic processes was made by the uptake level of 3H thymidine, 3H uridine, and 3H triptophan in the muscles. The experiment showed the followings: a) nucleic acids and protein synthesis stayed unchanged in the psoas; b) adrenalin stimulated the uptake of the radioactive precursors in the diaphragm and soleus, and c) the biosynthetic processes were inhibited in the myocardium by adrenalin administration. Though adrenalin is known to stimulate proteic synthesis in the skeletal muscle, our study showed that this process occurs only in certain types of muscles (with slow contraction). Inhibition of proteic synthesis in the myocardium in the presence of adrenalin might be one of the cellular mechanisms involved in cardiac failure.
Subject(s)
Catecholamines/physiology , Heart/growth & development , Muscle Development , Muscle, Skeletal/growth & development , Animals , DNA/biosynthesis , Epinephrine/pharmacology , Heart/drug effects , Male , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , Myocardium/metabolism , Protein Biosynthesis , Rats , Rats, Wistar , Thymidine/metabolism , Tritium , Tryptophan/metabolism , Uridine/metabolismABSTRACT
The medical, agricultural and scientific interest of the muscular tissue is well established in the literature. Its formation and function are essential for survival. It is also known that steroid hormones are involved in the growth, development and maturation of skeletal muscles (sexual hormones) as well as in the process of body adjustment to the stress factors in the environment (glucocorticoid hormones). Starting from these considerations, our experiment has made an attempt to clarify part of the mechanisms involved in the action of steroid hormones at muscle level. On this purpose, 3H thymidine and 3H uridine incorporation was followed up in various types of skeletal muscles (femoral biceps, diaphragmatic, psoas) from rats treated with steroid hormones. Though known as anabolic hormones, sexual hormones did not induce significant and persistent changes in the nucleic acid synthesis (NAS), except for testosterone which enhanced RNA synthesis only in the level femoral muscle after 21 days of administration. Progesterone and the glucocorticoid hormones are known as hormones of proteic catabolism but it seems that this effect is more marked in muscles whose structure predominantly consists of white fibres (rapid muscles), as confirmed by our experiment.
Subject(s)
DNA/biosynthesis , DNA/drug effects , Hormones/physiology , Muscles/metabolism , Animals , Female , Hormones/pharmacology , Male , Muscles/drug effects , Rats , Rats, Wistar , Thymidine/metabolism , Time Factors , TritiumABSTRACT
Integral radiophotographic detection was carried out in the territories of 5 randomly selected village dispensaries in 5 different counties. The action was performed in strictly operational conditions, without external experimental interferences. Stress was laid on the strict following of the methodological letter concerning radiophotography. The performing of integral radiophotographic detection in strictly operational conditions in the rural environment demonstrated the utility of these examinations in the present stage. The output obtained can be considered as satisfactory; local variations can be noted and this indicates the possibility of differentiating the conduct in various geographical areas.