Determination of blood volume in the mouse with 51Chromium-labelled erythrocytes

Sluiter, Willem; Oomens, L.W.M.; Brand, A.; Furth, R. van

doi:10.1016/0022-1759(84)90046-2

Cited by 41 publications

(27 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ACE.2 knockout mice have a total blood volume comparable with that of wild-type mice (58 µl/g vs. 56 µl/g). This value is similar to the total blood volumes of several strains of mice previously reported in the literature (14,19). However, ACE.2 knockout mice have a 25% reduction of red cell mass as compared with wild-type mice (22.7 µl/g ± 1.1 µl/g vs. 30.3 µl/g ± 1.7 µl/g, P < 0.01).…”

Section: Figuresupporting

confidence: 91%

See 1 more Smart Citation

Lack of angiotensin II–facilitated erythropoiesis causes anemia in angiotensin-converting enzyme–deficient mice

et al. 2000

View full text Add to dashboard Cite

IntroductionThe renin-angiotensin system plays a critical role in blood pressure regulation and fluid hemodynamics. Pharmacologic inhibitors of this system are routinely used to treat hypertension and congestive heart failure. One of the most controversial effects of the reninangiotensin system has been the interplay of this system with erythrocyte production. A variety of clinical reports have noted an association between activation of the renin-angiotensin system and increased erythropoiesis (1-3). These studies have come from analyses of patients with a variety of chronic diseases including chronic obstructive pulmonary disease, heart failure, and renal transplantation. Other investigators have suggested a link between angiotensin-converting enzyme (ACE) inhibitors and worsened anemia, particularly in patients with chronic renal failure (4-6). While research has focused on the interplay of the renin-angiotensin system and erythropoietin, no mechanistic explanation for these observations has been generally accepted.Central to the renin-angiotensin system is ACE, a peptidase that converts angiotensin I to angiotensin II (7). In mammals, most ACE is bound to tissues such as endothelium, but enzymatic cleavage results in a circulating form within plasma. In vitro, ACE is capable of cleaving many small peptides besides angiotensin I. However, in vivo, with the exception of bradykinin, the significance of nonangiotensin peptides as ACE substrates is not well understood. ACE is a protein with two independent catalytic domains. While both catalytic sites hydrolyze angiotensin I with roughly equal efficiency, the amino-and carboxy-terminal catalytic domains differ in their rate constants for other peptides.Using targeted homologous recombination in embryonic stem (ES) cells, our laboratory created two lines of mice with modifications of the ACE gene (8, 9). These animals are termed ACE.1 and ACE.2. Mice homozygous for the ACE.1 allele (ACE.1 knockout mice) are null for all ACE production. They have a marked reduction of blood pressure, and a renal lesion characterized by hypoplasia of the renal medulla and papilla. In contrast to this null phenotype, animals homozygous for the ACE.2 allele (ACE.2 knockout mice) have a partial restoration of ACE activity. These animals express a truncated ACE protein containing only the amino-terminal catalytic domain. Since this shortened ACE protein lacks the carboxy-terminal domain that normally anchors ACE to cell membranes, the ACE.2 protein is exported from cells into blood and other extracellular fluids. Thus, while the plasma of ACE.2 mice converts angiotensin I to angiotensin II with about 34% of the activity of wild-type mouse plasma, tissues such as the lung and kidney completely lack ACE protein or activity. The systolic blood pressure of ACE.2 knockout mice averaged 75 mmHg, as low as that of the ACE.1 knockout animals.Here, we investigate an unexpected finding concerning the phenotypes of both the ACE.1 and ACE.2 mice. These animals are anemic. ACE.2 knockout mice are a p...

show abstract

Section: Figuresupporting

confidence: 91%

“…The measurement of red cell mass and blood volume in mice using 51 Cr-labeled erythrocytes has been previously described (14,15). Briefly, whole blood was harvested from donor ACE.2 heterozygous mice and incubated with 100 µCi Na 51 CrO 4 for 30 minutes at room temperature.…”

Section: Figurementioning

confidence: 99%

Lack of angiotensin II–facilitated erythropoiesis causes anemia in angiotensin-converting enzyme–deficient mice

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Furthermore, this imaging approach was not sensitive enough to detect tracer in the blood that may have entered via the conventional pathway. The estimated maximum blood concentration of QC-1 (<0.45 lM; 3 lL of 280 lM QC-1/BSA divided by the total blood volume 85 ) may be below the detection limit in our experimental conditions. Furthermore, the background in the blood rich in oxyhemoglobin and deoxyhemoglobin may be too high to detect a minimal amount of the QC-1 signal.…”

Section: Discussionmentioning

confidence: 99%

Active Lymphatic Drainage From the Eye Measured by Noninvasive Photoacoustic Imaging of Near-Infrared Nanoparticles

Yücel

Cardinell

Khattak

et al. 2018

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

PURPOSE. To visualize and quantify lymphatic drainage of aqueous humor from the eye to cervical lymph nodes in the dynamic state. METHODS.A near-infrared tracer was injected into the right eye anterior chamber of 10 mice under general anesthesia. Mice were imaged with photoacoustic tomography before and 20 minutes, 2, 4, and 6 hours after injection. Tracer signal intensity was measured in both eyes and right and left neck lymph nodes at every time point and signal intensity slopes were calculated. Slope differences between right and left eyes and right and left nodes were compared using paired t-test. Neck nodes were examined with fluorescence optical imaging and histologically for the presence of tracer. RESULTS.Following right eye intracameral injection of tracer, an exponential decrease in tracer signal was observed from 20 minutes to 6 hours in all mice. Slope differences of the signal intensity between right and left eyes were significant (P < 0.001). Simultaneously, increasing tracer signal was observed in the right neck node from 20 minutes to 6 hours. Slope differences of the signal intensity between right and left neck nodes were significant (P ¼ 0.0051). Ex vivo optical fluorescence imaging and histopathologic examination of neck nodes confirmed tracer presence within submandibular nodes.CONCLUSIONS. Active lymphatic drainage of aqueous from the eye to cervical lymph nodes was measured noninvasively by photoacoustic imaging of near-infrared nanoparticles. This unique in vivo assay may help to uncover novel drugs that target alternative outflow routes to lower IOP in glaucoma and may provide new insights into lymphatic drainage in eye health and disease.

show abstract

“…The total blood volume of the mouse was about 1.2 mL. 29 Thus the concentration of EB in the blood stream was ϳ1%, corresponding to an absorption coefficient of ϳ1000 cm −1 at 610 nm, 30 which is ϳ20 times higher than that of blood ͑ϳ50 cm −1 ͒. Two PA images at 610 nm were acquired, one immediately after the dye injection and the other 30 min later.…”

Section: Spatially Continuous Capillary Imaging Using Evans Blue As Amentioning

confidence: 99%

Evans blue dye-enhanced capillary-resolution photoacoustic microscopy in vivo

Yao

Maslov

et al. 2009

J. Biomed. Opt.

View full text Add to dashboard Cite

Abstract. Complete and continuous imaging of microvascular networks is crucial for a wide variety of biomedical applications. Photoacoustic tomography can provide high resolution microvascular imaging using hemoglobin within red blood cells ͑RBCs͒ as an endogenic contrast agent. However, intermittent RBC flow in capillaries results in discontinuous and fragmentary capillary images. To overcome this problem, we use Evans blue ͑EB͒ dye as a contrast agent for in vivo photoacoustic imaging. EB has strong optical absorption and distributes uniformly in the blood stream by chemically binding to albumin. With the help of EB, complete and continuous microvascular networks-especially capillaries-are imaged. The diffusion dynamics of EB leaving the blood stream and the clearance dynamics of the EB-albumin complex are also quantitatively investigated.

show abstract

Determination of blood volume in the mouse with 51Chromium-labelled erythrocytes

Cited by 41 publications

References 5 publications

Lack of angiotensin II–facilitated erythropoiesis causes anemia in angiotensin-converting enzyme–deficient mice

Lack of angiotensin II–facilitated erythropoiesis causes anemia in angiotensin-converting enzyme–deficient mice

Active Lymphatic Drainage From the Eye Measured by Noninvasive Photoacoustic Imaging of Near-Infrared Nanoparticles

Evans blue dye-enhanced capillary-resolution photoacoustic microscopy in vivo

Contact Info

Product

Resources

About