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- Adem, Abdu, et al.
(författare)
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ANP and BNP Responses to Dehydration in the One-Humped Camel and Effects of Blocking the Renin-Angiotensin System
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:3, s. e57806-
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were to investigate and compare the responses of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) in the circulation of hydrated, dehydrated, and dehydrated losartan - treated camels; and to document the cardiac storage form of B-type natriuretic peptide in the camel heart. Eighteen male camels were used in the study: control or hydrated camels (n = 6), dehydrated camels (n = 6) and dehydrated losartan-treated camels (n = 6) which were dehydrated and received the angiotensin II (Ang II) AT-1 receptor blocker, losartan, at a dose of 5 mg/kg body weight intravenously for 20 days. Control animals were supplied with feed and water ad-libitum while both dehydrated and dehydrated-losartan treated groups were supplied with feed ad-libitum but no water for 20 days. Compared with time-matched controls, dehydrated camels exhibited a significant decrease in plasma levels of both ANP and BNP. Losartan-treated camels also exhibited a significant decline in ANP and BNP levels across 20 days of dehydration but the changes were not different from those seen with dehydration alone. Size exclusion high performance liquid chromatography of extracts of camel heart indicated that proB-type natriuretic peptide is the storage form of the peptide. We conclude first, that dehydration in the camel induces vigorous decrements in circulating levels of ANP and BNP; second, blockade of the renin-angiotensin system has little or no modulatory effect on the ANP and BNP responses to dehydration; third, proB-type natriuretic peptide is the storage form of this hormone in the heart of the one-humped camel.
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| 2. |
- Al Haj, Mahmoud, et al.
(författare)
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Effect of Dehydration in the Presence and Absence of the Angiotensin Receptor Blocker Losartan on Blood Constituents in the Camel
- 2011
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Ingår i: Journal of Medical Sciences. - : Hamdan Medical Journal. - 1996-3262 .- 1996-3270. ; 4:2, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Dromedary camels are extremely well adapted to periods of water deprivation. The physiological mechanisms underlying this adaptation, however, are imperfectly understood. It is likely that the renin-angiotensin system plays an important role although few studies have addressed this possibility in the camel. Accordingly, the effects of long term dehydration alone and with angiotensin II type 1 receptor blocker, losartan, on whole blood and serum constituents were studied in camels.Methods:Twenty eight male camels 3-4 years old were studied while under shade during summer in the Gulf-region, where the ambient temperature was above 40 degree Celsius. The camels were divided into three groups: a control group(n=6) was allowed free access to feed and water, a dehydration group (n=16) was given food ad-lib during 20days of total water deprivation, and a dehydration plus losartan (losartan) group (n=6) which received losartan 5mg/Kg daily by intravenous injection during 20 days of dehydration. Results: The body weight of the losartan group decreased by nearly 39.1% across dehydration whereas the reduction in body weight for the dehydration group was nearly 34.5% compared to controls. There was a significant increase in the packed cell volume (p<0.05) and leucocytes count (p<0.01) in the losartan group compared to controls. However, the mean corpuscular volume was significantly higher (p<0.05) in the dehydration group compared to controls. We observed major, statistically significant increases in serum urea (p<0.01) and creatinine (p<0.05) levels in the dehydration and losartan groups compared to controls. By the end of the period ofwater restriction, serum levels of gamma glutamyl transferase were significantly (p<0.01) lower in the losartan group compared to controls.Conclusion: The results of our experiment show that dehydration alone or in combination with Angiotensin II receptor blocker has major effects on the biochemical and hematological parameters of the camel blood.
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| 3. |
- Ali Haj, Mahmoud, et al.
(författare)
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Effects of Dehydration and Blockade of Angiotensin II AT1 Receptor on Stress Hormones and Anti-Oxidants in the one-humped camel
- 2013
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Ingår i: BMC Veterinary Research. - : Springer Science and Business Media LLC. - 1746-6148. ; 9, s. 232-
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Ali, Mahmoud Alhaj, et al.
(författare)
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Responses to Dehydration in the One-Humped Camel and Effects of Blocking the Renin-Angiotensin System
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:5, s. e37299-
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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