Responses to Dehydration in the One-Humped Camel and Effects of Blocking the Renin-Angiotensin System

Our objectives were to compare the levels of circulating electrolytes, hormones, and renal function during 20 days of dehydration in camels versus the level in non-dehydrated camels and to record the effect of blocking angiotensin II AT1 receptors with losartan during dehydration. Dehydration induced significant increments in serum sodium, creatinine, urea, a substantial fall in body weight, and a doubling in plasma arginine vasopressin (AVP) levels. Plasma aldosterone, however, was unaltered compared with time-matched controls. Losartan significantly enhanced the effect of dehydration to reduce body weight and increase serum levels of creatinine and urea, whilst also impairing the rise in plasma AVP and reducing aldosterone levels. We conclude that dehydration in the camel induces substantial increments in serum sodium, creatinine, urea and AVP levels; that aldosterone levels are altered little by dehydration; that blockade of angiotensin II type 1 receptors enhances the dehydration-induced fall in body weight and increase in serum creatinine and urea levels whilst reducing aldosterone and attenuating the rise in plasma AVP

Fourth World Heart Failure Congress 2014

Under the patronage of H. H. Sheikha Fatma Bint Mubarak, (Umm Al Amarat) President of Women General Union, Supreme Chancellor of the Family Development Foundation, President of the High Council for Motherhood and Childhood the Fourth World Heart Failure Congress was held on the 11th -13th December at the Danat Resort Hotel, Al-Ain, United Arab Emirates. The Congress was organized by the World Heart Failure Society in association with the Faculty of Medicine and Health Sciences, Tawam Hospital and United Arab Emirates Universit

Oxidative stress, inflammation, and DNA damage in multiple organs of mice acutely exposed to amorphous silica nanoparticles

Abderrahim Nemmar,1 Priya Yuvaraju,1 Sumaya Beegam,1 Javed Yasin,2 Elsadig E Kazzam,2 Badreldin H Ali3 1Department of Physiology, 2Department of Internal Medicine, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE; 3Department of Pharmacology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Al-Khoudh, Sultanate of Oman Abstract: The use of amorphous silica (SiO2) in biopharmaceutical and industrial fields can lead to human exposure by injection, skin penetration, ingestion, or inhalation. However, the in vivo acute toxicity of amorphous SiO2 nanoparticles (SiNPs) on multiple organs and the mechanisms underlying these effects are not well understood. Presently, we investigated the acute (24 hours) effects of intraperitoneally administered 50 nm SiNPs (0.25 mg/kg) on systemic toxicity, oxidative stress, inflammation, and DNA damage in the lung, heart, liver, kidney, and brain of mice. Lipid peroxidation was significantly increased by SiNPs in the lung, liver, kidney, and brain, but was not changed in the heart. Similarly, superoxide dismutase and catalase activities were significantly affected by SiNPs in all organs studied. While the concentration of tumor necrosis factor α was insignificantly increased in the liver and brain, its increase was statistically significant in the lung, heart, and kidney. SiNPs induced a significant elevation in pulmonary and renal interleukin 6 and interleukin-1 beta in the lung, liver, and brain. Moreover, SiNPs caused a significant increase in DNA damage, assessed by comet assay, in all the organs studied. SiNPs caused leukocytosis and increased the plasma activities of lactate dehydrogenase, creatine kinase, alanine aminotranferase, and aspartate aminotransferase. These results indicate that acute systemic exposure to SiNPs causes oxidative stress, inflammation, and DNA damage in several major organs, and highlight the need for thorough evaluation of SiNPs before they can be safely used in human beings. Keywords: amorphous silica nanoparticles, organ toxicity, oxidative stress, inflammation, DNA damag

Effects of Dehydration and Blockade of Angiotensin II AT1 Receptor on Stress Hormones and Anti-Oxidants in the one-humped camel

Our objectives were to document and compare plasma levels of Catecholamines, Cortisol,Glutathione and Malondialdehyde in camels after long term dehydration (20 days) in the presenceor absence of angiotensin II AT1 receptor blocker (Losartan) versus levels in non-dehydratedcamels; and to record the effects on glutathione and malondialdehyde activity in liver and kidneyhomogenate in the one-humped camel. Eighteen male camels were used in this study, sixcontrols, six dehydrated and treated with losartan (5mg/kg daily) and six were dehydrated withouttreatment. Our results revealed significant decrease (P<0.05) in plasma epinephrine level in bothtreated and dehydrated camels; while, Plasma norepinephrine showed significant increase in bothdehydrated groups (P< 0.01). Levels of plasma dopamine were also significantly increased (P<0.01) in both dehydrated groups compared to control camels.Plasma levels of cortisol increased significantly across dehydration with or without losartanadministration (P<0.01) compared with time-matched levels in control camels. Losartan had nosignificant modulating effect on the cortisol response to dehydration.Plasma, liver and kidney homogenates revealed significant increase (P<0.05) in glutathione levelsin both dehydrated groups compared to control.Plasma, liver and kidney homogenates for malondialdehyde levels in both treated and dehydratedcamels also showed significant increase (P<0.05 & P<0.01) compared to controls.In conclusion, our study demonstrates that the effect of dehydration with or without losartaninduced oxidative stress in these camels, leading to significant changes in plasma catecholaminesand cortisol levels, together with significant increments in glutathione and malondialdehydeactivities in plasma, liver and kidney homogenate to counter act the damaging effect of the freeradicals in the dehydrated camels

Short-Term Systemic Effects of Nose-Only Cigarette Smoke Exposure in Mice: Role of Oxidative Stress

Background/Aims: Long–term cigarette smoking (CS) is a major risk factor for respiratory and cardiovascular diseases, and is also known to adversely affect other organs. However, data on the systemic effects of short-term CS exposure (STCSE) are scarce. Presently, using a nose-only exposure system, we evaluated the systemic effects of STCSE in mice. Methods: We assessed the effects of CS generated by 9 consecutive cigarettes per day for 4 days in a nose-only exposure system on cardiovascular, hepatic and renal endpoints evaluated on day 5 in mice. Control mice were exposed to air only. Results: CS significantly increased systolic blood pressure and decreased total nitric oxide plasma concentration. Circulating platelets and erythrocyte numbers were also increased. However, STCSE did not significantly increase thrombosis in pial arterioles and venules. STCSE significantly raised plasma alanine aminotransferase and gamma glutamyl transpeptidase activities, but did not affect urea or creatinine concentrations. Interestingly, while STCSE enhanced the production of reactive oxygen species in heart and kidney and lipid peroxidation in heart, liver and kidneys, it also enhanced the antioxidant activity of superoxide dismutase, probably indicating that STCSE causes adaptive reactions to counterbalance the potentially damaging action of oxygen radicals induced by STCSE. Conclusion: These results suggest that STCSE causes blood pressure increase, hepatotoxicity and oxidative stress in the heart, liver and the kidneys. These data provide information on the initial steps leading to the systemic effects of STCSE, a stage at which the diseases may likely be reversed