Luiz Alberto Ferreira Ramos

Nutritional leucine supplementation attenuates cardiac failure in tumour‐bearing cachectic animals

The condition known as cachexia presents in most patients with malignant tumours, leading to a poor quality of life and premature death. Although the cancer‐cachexia state primarily affects skeletal muscle, possible damage in the cardiac muscle remains to be better characterized and elucidated. Leucine, which is a branched chain amino acid, is very useful for preserving lean body mass. Thus, this amino acid has been studied as a coadjuvant therapy in cachectic cancer patients, but whether this treatment attenuates the effects of cachexia and improves cardiac function remains poorly understood. Therefore, using an experimental cancer‐cachexia model, we evaluated whether leucine supplementation ameliorates cachexia in the heart.

Vascular Response of Ruthenium Tetraamines in Aortic Ring from Normotensive Rats

Background Ruthenium (Ru) tetraamines are being increasingly used as nitric oxide (NO) carriers. In this context, pharmacological studies have become highly relevant to better understand the mechanism of action involved. Objective To evaluate the vascular response of the tetraamines trans-[RuII(NH3)4(Py)(NO)]3+, trans-[RuII(Cl)(NO) (cyclan)](PF6)2, and trans-[RuII(NH3)4(4-acPy)(NO)]3+. Methods Aortic rings were contracted with noradrenaline (10−6 M). After voltage stabilization, a single concentration (10−6 M) of the compounds was added to the assay medium. The responses were recorded during 120 min. Vascular integrity was assessed functionally using acetylcholine at 10−6 M and sodium nitroprusside at 10−6 M as well as by histological examination. Results Histological analysis confirmed the presence or absence of endothelial cells in those tissues. All tetraamine complexes altered the contractile response induced by norepinephrine, resulting in increased tone followed by relaxation. In rings with endothelium, the inhibition of endothelial NO caused a reduction of the contractile effect caused by pyridine NO. No significant responses were observed in rings with endothelium after treatment with cyclan NO. In contrast, in rings without endothelium, the inhibition of guanylate cyclase significantly reduced the contractile response caused by the pyridine NO and cyclan NO complexes, and both complexes caused a relaxing effect. Conclusion The results indicate that the vascular effect of the evaluated complexes involved a decrease in the vascular tone induced by norepinephrine (10−6 M) at the end of the incubation period in aortic rings with and without endothelium, indicating the slow release of NO from these complexes and suggesting that the ligands promoted chemical stability to the molecule. Moreover, we demonstrated that the association of Ru with NO is more stable when the ligands pyridine and cyclan are used in the formulation of the compound.

Long‐term leucine supplementation aggravates prolonged strenuous exercise‐induced cardiovascular changes in trained rats

What is the central question of this study? Can long‐term leucine supplementation prevent prolonged strenuous endurance exercise induced cardiac injury? What is the main finding and its importance? Prolonged endurance exercise does not seem to exceed cardiac energetic capacity, hence it does not represent an energy threat to this organ, at least in trained subjects. However, it may induce, in susceptible individuals, a state of cardiac electrical instability, which has been associated with ventricular arrhythmias and sudden cardiac death. This situation might be worsened when combined with leucine supplementation, which leads to increased blood pressure and cardiac injury. Leucine supplementation failed to prevent cardiac fatigue symptoms and may aggravate prolonged strenuous exercise‐induced cardiovascular disturbances in trained rats.

APPLICATION OF THEORY IN PRACTICE: INTEGRATING AREAS - exact and biological- IN GRADUATE - Study of ECC in hypertensive rats.

Bruna Sabrina Hergert (IC), Ana Gabriela Conceição-Vertamatti (PQ), Larissa Yuri Ishizu (PQ), Luiz Alberto Ramos (PQ), Gustavo Trevisan Costa (IC), Fernando Canova (PQ). Laura Leticia Ramos Rifo (PQ), Dora M. Grassi-Kassisse (PQ). Abstract Exact and Biological sciences are areas of expertise that complement each other. The associations between these areas are little explored in the formation of graduate student. Proposals to recruit students of exact for help with the analysis of the data obtained in Labeest generated great interest of applicants’ scholarship BAS-SAE. Data analysis electrocardiography of models of hypertension in rats was carried out by a student of statistics, which can apply their knowledge acquired during their training.