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C Burtea

Publications and source records attributed to C Burtea.

8 recordsLinked to original sources
PubMed1998

Spin-spin relaxation times in myocardial hypertrophy induced by endocrine agents in rat.

Magnetic resonance techniques afford a significant advantage for noninvasive diagnosis of cardiovascular pathology. The purpose of our present study was to assay the proton nuclear magnetic resonance (1H-NMR) sensitivity in the differential diagnosis of certain endocrine cardiovascular complications. In this context, we investigated the water state and content in the hypertrophied myocardium. Male and female Wistar rats were treated with different hormones (hydrocortisone acetate, testosterone, estradiol, thyroid hormones) in combination with isoproterenol (a synthetic catecholamine that induces myocardial ischemia and hypertrophy). The animals were sacrificed after 20 days of treatment and samples of integral myocardium and left ventricular myocardium were analyzed on a 1H-NMR AREMI spectrometer (0.6 T; proton resonance at 25 MHz). The estimation of T2 was made by Carr Purcell-Meiboom-Gill pulse sequence. The data were fitted to a bi-exponential curve, yielding short (T21) values for bound water and long (T22) values for free water. In order to evaluate the myocardial hypertrophy, the following ratios were calculated: integral myocardium to body weight; left ventricle to body weight; left ventricle to integral myocardium. The first two ratios were also calculated for dried tissue, in order to estimate its contribution to myocardial hypertrophy. Our findings demonstrate that myocardial hypertrophy is associated with a decrease of T22, as a consequence of the increase in the dried component (i.e. proteins) of the tissue, while the total tissue water (H2Ot%), measured by gravimetry) was not significantly modified. Nevertheless, it is reasonable that the increase in the protein content would be proportional with the increase in H2Ot%. The decrease of T21 seems to be proportional with the level of left ventricle hypertrophy in female groups. The 1H-NMR measurements were much sensitive for the differential diagnosis of myocardial hypertrophy in the case of left ventricle.

Adrenergic beta-Agonists↗
PubMed1993

The role of catecholamines in muscular growth.

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.

Animals↗
PubMed1993

The role of catecholamines in the distribution of steroid hormones in the striated and cardiac muscle.

Loss of muscular strength is a well-known component of the clinical picture many endocrine diseases and is often their predominant aspect. It has recently been proved that the cytoplasmatic receptors for steroid hormones (SH) are artefacts of the fixation techniques and that they are attached to the internal surface of the cell membrane. Our experiment was made on male and female. Wistar rats which were tested for the level of radioactively labelled steroid hormones (3H and HD3H hydrocortisone; 3H testosterone, TS3H; 3H estrone, FS3H) in various types of skeletal muscles (from rapid to slow) and cardiac muscle before and after adrenalin administration. Before adrenalin administration one noticed: (a) a significantly higher level of HD3H (p < 0.05) in the female skeletal muscle; (b) in the femoral biceps and psoas, a significantly higher distribution of TS3H in males (p < 0.01), whereas in the diaphragm and the heart, there were no significant differences between sexes; (c) there are significant differences between sexes as regards the ES3H level in any of the studied muscles. After adrenalin administration there was a significant decrease in the level of labelled SH uptake in all experimental schemes. It is possible that adrenalin block the HS diffusion through the plasma membrane or even their binding to specific receptors.

Animals↗
PubMed1992

Steroid hormones control on nucleic acid biosynthesis in skeletal muscle.

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.

Animals↗
PubMed1991

Influence of sex and glucocorticoid hormones on 3H cholesterol uptake in the aortic wall and 3H adrenaline in the brain.

The mechanisms involved in the atherogenesis process and the connection of the latter with stress were studied, by trying to elucidate the difference in the response of the two sexes to the causative factors. To this purpose, the role of the sex hormones (testosterone, estradiol, progesterone) and glucocorticoids (hydrocortisone hemisuccinate) in 3H cholesterol uptake in the aortic wall and 3H adrenaline in the brain was investigated. In males, the results show that these hormones favoured the uptake of the two markers whose level was significantly raised (p greater than 0.05; p greater than 0.01) as against the controls all along the 20 days of treatment. In females, the level of 3H cholesterol in the aorta and 3H adrenaline in the brain had a statistical significance (p greater than 0.05) only in the first days of treatment but after the 6th day it began to decline.

Animals↗
PubMedDate not supplied

Research on red cell membrane permeability in arterial hypertension.

Arterial hypertension, including the elucidation of hypertension pathogenic mechanisms involving elements in the composition of the blood, continues to represent a topical research area. Recent work, such as nuclear magnetic resonance studies looking into red cell permeability, illustrates the presence of modifications of red cell permeability to water (RCPW) related to the stage of arterial hypertension. The identification of a significant increase of RCPW compared to that present in the population with normal arterial pressure values can be useful both in early diagnosis and in warning about a possible predisposition for this condition. At the same time, the dynamic investigation of protonic relaxation time of both intra- and extra-erythrocytic water, the assessment of proton exchange time across the red cell and the calculation of permeability to water enable one not only to diagnose arterial hypertension but also to ascertain the evolution of the disease, its complications and the effectiveness of anti-hypertensive medication. Our studies have also proven the existence of a correlation between the values of systolic arterial pressure and red cell permeability to water. The curve describing the interdependence of the two values has the shape of a bell, in the case of males. The peak of the curve is reached for a systolic pressure of 160 mmHg and gets below the values of the control group in the case of systolic pressures above 200 mmHg. The RCPW test can also be considered a valuable indicator in evaluating the risk of stroke in hypertensive patients. In the chronic therapy of arterial hypertension with various types of anti-hypertensive drugs, one can note differences in the RCPW values related to the effectiveness of the respective medication, to the clinical form and stage of the disease, the sex of the patient as well as to the existence of cerebro-vascular complications.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

Activity of glutathione-s-transferase, gammaglutamiltransferase and catalase in the erythrocytic membrane in arterial hypertension.

Our clinical-biological study has been performed in patients with various clinical forms of arterial hypertension (AHT), as well as with sequelae-type complications from stroke that had occurred during the evolution of the disease. We performed biological determinations of the activity of four erythrocytic enzymes: glutathione-s-transferase (GST), catalase, gamma-glutamyltransferase (GGT), and lactate dehydrogenase (LDH). The results point to the existence of individual values and also of important differences depending on the presence of arterial hypertension complications. We found a moderate but significant increase of erythrocytic GGT in hypertensive patients compared to healthy controls. Erythrocytic GST and LDH were decreased in patients vs controls. The results of the enzymatic, erythrocyitc activities of GST, GGT, catalase and LDH can also be correlated with the parameters of erythrocyitc membrane permeability and with the thiolic groups, fibrinogen and ionic calcium concentration. The data described in this paper suggest the possible involvement of the disturbances mentioned above in the etiopathogeny of AHT.

Adult↗