Role of Angiotensin II in Hemorrhagic Hypotension in the Rat

Author Institution: Department of Physiology, Wright State UniversityThe purpose of this study was to evaluate the role of the renin-angiotensin system in the acute regulation of blood pressure following hemorrhage in the anesthetized rat. Eleven Sprague-Dawley rats were anesthetized with sodium pentobarbital. After control blood pressure recordings from the femoral artery were made, the rats were hemorrhaged 6 ml/kg body weight. Forty minutes after hemorrhage, the Angiotensin II antagonist, l-SAR-8-ALA-Angiotensin II (saralasin), was infused (10 /Ltg/min/kg) for 35 min. Hemorrhage resulted in a 53% decrease in blood pressure which recovered to 82% of the control blood pressure in 40 minutes. Infusion of saralasin resulted in a 24% decrease (p <0.01) in blood pressure within 15 min. Recovery from saralasin infusion occurred within 10 min as blood pressure increased back to control values. A second group of 5 rats was not hemorrhaged but was infused with saralasin. There were no significant changes in blood pressure; although, a tendency to decrease was noted reflecting the increase in plasma renin activity which occurs with anesthesia. It was concluded that the renin-angiotensin system can respond rapidly to a hypotensive event and aid in the restoration of blood pressure within minutes

A multivariate analysis of serum nutrient levels and lung function

<p>Abstract</p> <p>Background</p> <p>There is mounting evidence that estimates of intakes of a range of dietary nutrients are related to both lung function level and rate of decline, but far less evidence on the relation between lung function and objective measures of serum levels of individual nutrients. The aim of this study was to conduct a comprehensive examination of the independent associations of a wide range of serum markers of nutritional status with lung function, measured as the one-second forced expiratory volume (FEV₁).</p> <p>Methods</p> <p>Using data from the Third National Health and Nutrition Examination Survey, a US population-based cross-sectional study, we investigated the relation between 21 serum markers of potentially relevant nutrients and FEV₁, with adjustment for potential confounding factors. Systematic approaches were used to guide the analysis.</p> <p>Results</p> <p>In a mutually adjusted model, higher serum levels of antioxidant vitamins (vitamin A, beta-cryptoxanthin, vitamin C, vitamin E), selenium, normalized calcium, chloride, and iron were independently associated with higher levels of FEV₁. Higher concentrations of potassium and sodium were associated with lower FEV₁.</p> <p>Conclusion</p> <p>Maintaining higher serum concentrations of dietary antioxidant vitamins and selenium is potentially beneficial to lung health. In addition other novel associations found in this study merit further investigation.</p