Diverse effects of renal denervation on ventricular hypertrophy and blood pressure in DOCA-salt hypertensive rats

Cardiac hypertrophy that accompanies hypertension seems to be a phenomenon of multifactorial origin whose development does not seem to depend on an increased pressure load alone, but also on local growth factores and cardioadrenergic activity. The aim of the present study was to determine if sympathetic renal denervation and its effects on arterial pressure level can prevent cardiac hypertrophy and if it can also delay the onset and attenuate the severity of deoxycorticosterone acetate (DOCA)-salt hypertension. DOCA-salt treatment was initiated in rats seven days after uninephrectomy and contralateral renal denervation or sham renal denervation. DOCA (15 mg/kg, sc) or vehicle (soybean oil, 0.25 ml per animal) was administered twice a week for two weeks. Rats treated with DOCA or vehicle (control) were provided drinking water containing 1 percent NaCl and 0.03 percent KCl. At the end of the treatment period, mean arterial pressure (MAP) and heart rate measurements were made in conscious animals. Under ether anesthesia, the heart was removed and the right and left ventricles (including the septum) were separated and weighed. DOCA-salt treatment produced a significant increase in left ventricular weight/body weight (LVW/BW) ratio (2.44 + 0.09 mg/g) and right ventricular weight/body weight (RVW/BW) ratio (0.53 + 0.01 mg/g) compared to control (1.92 + 0.04 and 0.48 + 0.01 mg/g, respectively) rats. MAP was significantly higher (39 percent) in DOCA-salt rats. Renal denervation prevented (P>0.05) the development of hypertension in DOCA-salt rats but did not prevent the increase in LVW/BW (2.27 + 0.03 mg/g) and RVW/BW (0.52 + 0.01 mg/g). We have shown that the increase in arterial pressure level is not responsible for cardiac hypertrophy, which may be more related to other events associated with DOCA-salt hypertension, such as an increase in cardiac sympathetic activity.

Binding of heparin and compound Y to endothelial cells stimulates the synthesis of an antithrombotic heparan sulfate proteoglycan

The mechanism by which heparin and antithrombotic agents, including a cyclic octaphenolsufonic acid (compound Y), stimulate the synthesis of an antithrombotic heparan sulfate by endothelial cells in culture was investigated. Compound Y increases the amount of heparan sulfate from the cell surface and secreted to the endothelial cell receptors at a concentration of 0.16µM for heparin and 2.7µM for compound Y. The kinetic binding constants (Ks) for compound Y and heparin were 1,333 nM and 42 nM, respectively. It was also shown that both compounds bind to the same receptors. The Scatchard plots indicated that 1,319 nmoles compound Y and 35 nmoles heparin bound per microgram cell protein, indicating that 40-fold more molecules of compound Y bound to the receptors when compared to heparin. No significant internalization of the compounds was observed

A doença de Chagas em motoristas de táxi na cidade de Uberlândia / Chagas' disease in taxi drivers in the city of Uberlandia

A prevalencia de sorologia positiva para a doenca de Chagas foi pesquisada em 152 motoristas de taxi de Uberlandia (MG). Houve 21 individuos (13,8%) com diagnostico sorologico de infeccao pelo Trypanosoma cruzi. Destes, 16 casos foram avaliados clinicamente, pelo eletrocardiograma (ECG) convencional e pelo estudo radiologico do torax. Todos eram assintomaticos 9 tinham arritmias cardiacas "benignas" pelo ECG (2 dos quais, com area cardiaca aumentada), 7 mostraram ECG e radiografias do torax normais. Ressalta-se a alta prevalencia da tripanosomiase na amostra. Discute-se a conduta medico-trabalhista a assumir diante dos casos positivos e a necessidade da inclusao de exames laboratoriais para diagnostico da doenca de Chagas, na rotina para a obtencao de carteira de motorista (pelo menos para profissionais) nas areas endemicas