Arterial entrance and metabolism of free and esterified plasma cholesterol measured in vivo in experimental animals by a dual isotope method

1979 ◽  
Vol 32 (2) ◽  
pp. 129-139 ◽  
Author(s):  
Steen Stender
Keyword(s):  
Plasma Cholesterol ◽  
Experimental Animals ◽  
Dual Isotope ◽  
Isotope Method

scholarly journals Challenging in Rats the Use of 13C Spirulina as Reference Protein for the Dual Isotope Method to Determine Amino Acid Bioavailability (P08-061-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Romain Tessier ◽  
Nadezda Khodorova ◽  
Juliane Calvez ◽  
Daniel Tomé ◽  
Claire Gaudichon
Keyword(s):  
Amino Acid ◽  
Goat Milk ◽  
Protein Digestibility ◽  
Male Rats ◽  
National Agency ◽  
Dual Isotope ◽  
Isotope Method ◽  
Reference Protein ◽  
Bonferroni Test

Abstract Objectives In order to establish DIAAS in humans, the FAO recommended to develop a new method to measure indispensable amino acid (IAA) digestibility. This method uses two isotopic labeling, one for the protein to test and one for a reference protein. Spirulina was chosen as the 13C reference protein due to its commercial availability and affordability. However, the real digestibility of spirulina protein has not been measured in vivo. This work aims to assess the digestibility of spirulina and its repeatability in different meal tests in rats. Methods 23 Wistar male rats were fed a test meal containing 0.5 g of 15 N protein from either spirulina (n = 7), sunflower n = 8) or goat milk isolate (n = 8) and 10 mg of 13C labeled spirulina. Rats were euthanized 6 h after the meal and their digestive luminal contents (stomach, small intestine, ileum, caecum, colon) were collected. Protein digestibility was determined for the test and the reference proteins by measuring 15 N and 13C enrichments in the digesta by EA-IRMS. Caecal IAA digestibility of 13C spirulina was determined by measuring the quantity of AA in the caecum by UPLC and the 13C enrichment in AA by GC-C-IRMS. Group effects were tested using one way ANOVA and differences between groups using Bonferroni test. Results Six hours after ingestion, most of the dietary 15 N and 13C were found in the caecum and colon. But there at least twice more 15 N nitrogen in the caecum and colon in the spirulina group than in the two other groups. Therefore, spirulina protein digestibility (86.0 ± 0.7%) was lower (P < 0.001) than sunflower (95.1 ± 0.5%) and goat milk digestibility (97.2 ± 0.2%). 13C spirulina digestibility tended to be different (P = 0.06) when mixed to spirulina (90.6 ± 0.6%), sunflower (88.8 ± 0.5%) or goat milk (89.0 ± 0.5%) isolates. The caecal IAA digestibility of 13C spirulina was lower in the spirulina group than in sunflower and goat milk groups for every IAA tested, and the mean was 91.6 ± 0.2% for sunflower, 91.4 ± 0.4% for goat milk and 85.4 ± 0.6% for spirulina. Conclusions Spirulina protein is of lower digestibility than other animal or plant proteins. Protein and amino digestibility of a tracer dose of 13C spirulina appears to vary depending on the protein component of the meal. These results question the use of spirulina as a reference protein for the dual isotope method. Funding Sources French Research National Agency (ANR), SOFIPROTEOL. Supporting Tables, Images and/or Graphs

scholarly journals Plasma cholesterol lowering action of bile acid binding polymers in experimental animals

1960 ◽  
Vol 1 (5) ◽  
pp. 469-473 ◽  
Author(s):  
DavidM. Tennent ◽  
Henry Siegel ◽  
MaryE. Zanetti ◽  
GuntherW. Kuron ◽  
WaltherH. Ott ◽  
...  
Keyword(s):  
Bile Acid ◽  
Plasma Cholesterol ◽  
Cholesterol Lowering ◽  
Experimental Animals ◽  
Bile Acid Binding

scholarly journals Circulating Markers Reflect Both Anti- and Pro-Atherogenic Drug Effects in ApoE-Deficient Mice

2008 ◽  
Vol 3 ◽  
pp. BMI.S632 ◽  
Author(s):  
Birong Liao ◽  
Eileen McCall ◽  
Karen Cox ◽  
Chung-Wein Lee ◽  
Shuguang Huang ◽  
...  
Keyword(s):  
Whole Blood ◽  
Plasma Cholesterol ◽  
Drug Effects ◽  
Drug Efficacy ◽  
Vascular Wall ◽  
Atherosclerotic Plaques ◽  
Protein Markers ◽  
Novel Approach ◽  
Coa Reductase

Background Current drug therapy of atherosclerosis is focused on treatment of major risk factors, e.g. hypercholesterolemia while in the future direct disease modification might provide additional benefits. However, development of medicines targeting vascular wall disease is complicated by the lack of reliable biomarkers. In this study, we took a novel approach to identify circulating biomarkers indicative of drug efficacy by reducing the complexity of the in vivo system to the level where neither disease progression nor drug treatment was associated with the changes in plasma cholesterol. Results ApoE-/- mice were treated with an ACE inhibitor ramipril and HMG-CoA reductase inhibitor simvastatin. Ramipril significantly reduced the size of atherosclerotic plaques in brachiocephalic arteries, however simvastatin paradoxically stimulated atherogenesis. Both effects occurred without changes in plasma cholesterol. Blood and vascular samples were obtained from the same animals. In the whole blood RNA samples, expression of MMP9, CD14 and IL-1RN reflected pro-and anti-atherogenic drug effects. In the plasma, several proteins, e.g. IL-1β, IL-18 and MMP9 followed similar trends while protein readout was less sensitive than RNA analysis. Conclusion In this study, we have identified inflammation-related whole blood RNA and plasma protein markers reflecting anti-atherogenic effects of ramipril and pro-atherogenic effects of simwastatin in a mouse model of atherosclerosis. This opens an opportunity for early, non-invasive detection of direct drug effects on atherosclerotic plaques in complex in vivo systems.

scholarly journals Application of Echocardiography on Transgenic Mice with Cardiomyopathies

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
G. Chen ◽  
Y. Li ◽  
J. Tian ◽  
L. Zhang ◽  
P. Jean-Charles ◽  
...  
Keyword(s):  
Heart Failure ◽  
Transgenic Mice ◽  
Tissue Doppler ◽  
Doppler Imaging ◽  
Cellular Mechanisms ◽  
Embryonic Mouse ◽  
Experimental Animals ◽  
Therapeutic Outcomes ◽  
And Function

Cardiomyopathies are common cardiac disorders that primarily affect cardiac muscle resulting in cardiac dysfunction and heart failure. Transgenic mouse disease models have been developed to investigate the cellular mechanisms underlying heart failure and sudden cardiac death observed in cardiomyopathy cases and to explore the therapeutic outcomes in experimental animals in vivo. Echocardiography is an essential diagnostic tool for accurate and noninvasive assessment of cardiac structure and function in experimental animals. Our laboratory has been among the first to apply high-frequency research echocardiography on transgenic mice with cardiomyopathies. In this work, we have summarized our and other studies on assessment of systolic and diastolic dysfunction using conventional echocardiography, pulsed Doppler, and tissue Doppler imaging in transgenic mice with various cardiomyopathies. Estimation of embryonic mouse hearts has been performed as well using this high-resolution echocardiography. Some technical considerations in mouse echocardiography have also been discussed.

scholarly journals Are Platelet Aggregation Tests the Best Way to Assess New Drugs for Arterial Disease

2018 ◽  
Vol 1 (1) ◽  
pp. 01-03
Author(s):  
Mark I. M. Noble
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Platelet Rich Plasma ◽  
New Drugs ◽  
In Vitro Test ◽  
In Vivo Efficacy ◽  
Experimental Animals ◽  
Stenosed Artery

Over many years, laboratory testing of platelet aggregability have been carried out in attempts to develop drugs that would prevent thrombosis in arteries. The problems encountered included the question of methodology. Blood samples have to be anticoagulated in order to study the platelets. Anti-coagulation with citrate and tests on derived platelet rich plasma did not correlate at all well with thrombus growth in the stenosed coronary arteries of experimental animals and citrate removes the calcium ions which are vital for platelet function. Anticoagulation with heparin also interfered with platelet function, so that now, hirudins are the preferred anticoagulant. However it was observed that if, instead of stimulating platelet aggregation with adrenaline or ADP, serotonin was applied to the preparation, very little aggregation took place in spite of serotonin 5HT2A antagonists being the most potent inhibitors of thrombus growth in experimental animals. Another indicator that primary platelet agggregation is not a predictor of in vivo efficacy was the finding that 5HT2A antagonism inhibited aggregate growth. In a stenosed artery the platelets are activated by increased shear stress and blood turbulence with release of platelet serotonin causing positive feedback activation of more platelets. At present, there does not seem to be a bench in vitro test that accurately predicts in vivo efficacy in stenosed artery occlusive thrombosis.

scholarly journals Inhibition of intravascular fibrin deposition by dipyridamole in experimental animals

Blood ◽  
1975 ◽  
Vol 45 (4) ◽  
pp. 569-575
Author(s):  
V Gurewich ◽  
B Lipinski ◽  
R Wetmore
Keyword(s):  
Reticuloendothelial System ◽  
Experimental Models ◽  
Significant Inhibition ◽  
Fibrin Deposition ◽  
Experimental Animals ◽  
Fibrin Monomer

Intravascular fibrin deposition was induced in rabbits by endotoxin, the infusion of fibrin monomer (FM), and by the infusion of thrombin and EACA. A previously developed radioisotope technique was used to measure the fibrin deposits in various organs. Dipyridamole treatment of rabbits caused significant inhibition of fibrin deposition in all three experimental models. The drug also inhibited platelet consumption and, in the thrombin- and EACA-infused animals, fibrinogen consumption as well. The results obtained with dipyridamole were compared with the effect of thorotrast. It was concluded from this comparison that the effect of dipyridamole could not be attributed to inhibition of the reticuloendothelial system. It is postulated that dipyridamole inhibits the final step at which soluble FM is precipitated as fibrin in vivo.

Abstract 49: Elevating Apolipoprotein A-I Levels Promotes Atherosclerosis Regression in Diabetic Mice by Inhibiting Proliferation of Bone Marrow Monocyte Precursors

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Tessa J Barrett ◽  
Emilie Distel ◽  
Yoscar Ogando ◽  
Yaritzy M Astudillo ◽  
Jianhua Liu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transgenic Mice ◽  
Plasma Cholesterol ◽  
Atherosclerotic Lesion ◽  
Lipid Lowering ◽  
Diabetic Mice ◽  
Blood Monocytes ◽  
Post Surgery ◽  
Lesion Regression

Diabetes is a primary risk factor for cardiovascular diseases (CVD) and in clinical imaging studies is shown to impair the resolution of CVD, a process termed regression. We have also reported this failure of lesion regression in mouse models of diabetes, despite effective lipid lowering. This, in part, can be attributed to diabetes-driven monocytosis promoting continued monocyte infiltration into plaques. In non-diabetic settings apolipoprotein (apo) A-I and high-density lipoprotein (HDL) suppress leukocytosis and promote lesion regression. As low apoA-I/HDL is a typical feature of diabetic dyslipidemia this study aimed to establish whether raising apoA-I/HDL levels in vivo is an effective approach to reduce diabetes-driven leukocytosis and promote lesion regression. Aortic arches from hyperlipidemic Ldlr -/- mice were transplanted into WT, diabetic WT, and diabetic human apoA-I-overexpressing transgenic mice (transgenic mice have a 3-fold increase in HDL-cholesterol), and lesion composition assessed 2 weeks post-surgery. Following aortic transplantation into WT mice (i.e. normal lipid levels) we found regression, as assessed by change in plaque macrophage (mΦ) content relative to baseline control mice was achieved (68% mΦ reduction, P<0.001). Regression was impaired when aortas were transplanted into diabetic WT recipients (50% mΦ reduction, P<0.01). However, raising apoA-I/HDL levels in the setting of diabetes restored regression in diabetic mice (62% mΦ reduction, P<0.001). In vivo monocyte/mΦ trafficking analyses revealed that elevating apoA-I/HDL levels in diabetes improves atherosclerosis regression by reducing monocyte entry by 60% (P<0.01), and promoting mΦ egress from lesions (30% increase). We also found that greater apoA-I/HDL reduced blood monocytes by decreasing the proliferation of monocyte progenitors in the bone marrow (15-20% reduction, P<0.05), explaining, in part, how apoA-I/HDL promotes regression. Raising apoA-I/HDL levels promotes atherosclerotic lesion regression in diabetic mice. This may serve as a therapeutic strategy for patients with diabetes, who unlike WT mice, have reduced HDL levels and remain at an elevated risk for CVD despite effective plasma cholesterol lowering.

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