Simultaneous Three-Dimensional Vascular and Tubular Imaging of Whole Mouse Kidneys With X-ray μCT

Kuo, Willy; Le, Ngoc An; Spingler, Bernhard; Wenger, Roland H.; Kipar, Anja; Hetzel, Udo; Schulz, Georg; Müller, Bert; Kurtcuoglu, Vartan

doi:10.1017/s1431927620001725

Cited by 8 publications

(12 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As an example from our own work, imaging blood vessels with 4 µm voxel size with a General Electric Phoenix nanotom m requires around 80 mg iodine/ml inside the vasculature in order to image a 1 cm 3 large volume with sufficient contrast for segmentation. 4 This is several orders of magnitude higher than contrast agents for magnetic resonance imaging (around 0.5 mg gadolinium/ml) 5 or fluorescence microscopy (< 1 µg antibody/ml) 6 .…”

Section: Challenges and Design Considerationsmentioning

confidence: 94%

“…The expected molecular weight was 20 kDa, below the minimum molecular weight of 65 kDa required to avoid glomerular filtration (Figure 1). The perfusion surgery was performed as described in Kuo et al 4 . Kidneys were mounted in 1 % agarose in 1.5 ml microcentrifugation tubes and µCT images were acquired with a General Electric Phoenix nanotom m, using an acceleration voltage of 60 kV, a current of 310 µA and 4.4 µm pixel size.…”

Section: Methodology 41 Mouse Kidney With Contrast Agent Below the Gl...mentioning

confidence: 99%

“…The kidneys of a C57BL/6J mouse were perfused via the abdominal aorta with a mixture of 4.8 % gelatin and 80 mg iodine/ml of a precursor molecule of the polymeric contrast agent XlinCA (Compound 3 of Le et al 2 ) as described in Kuo et al 4 . Kidneys were mounted in 4.8 % gelatin in 1.5 ml and imaged using a PerkinElmer Quantum FX in vivo µCT with an acceleration voltage of 70 kV, a current of 200 µA, 20 µm pixel size and a scan time of 3 minutes (Figure 3).…”

Section: Longitudinal Study Of a Mouse Kidney With Non-fixable Contra...mentioning

confidence: 99%

See 2 more Smart Citations

Tomographic imaging of microvasculature with a purpose-designed, polymeric x-ray contrast agent

Kuo

Spingler

et al. 2022

Developments in X-Ray Tomography XIV

Self Cite

View full text Add to dashboard Cite

Imaging of microvasculature is primarily performed with X-ray contrast agents, owing to the wide availability of absorption-contrast laboratory source µCT compared to phase contrast capable devices. Standard commercial contrast agents used in angiography are not suitable for high-resolution imaging ex vivo, however, as they are small molecular compounds capable of diffusing through blood vessel walls within minutes. Large nanoparticle-based blood pool contrast agents on the other hand exhibit problems with aggregation, resulting in clogging in the smallest blood vessels. Injection with solidifying plastic resins has, therefore, remained the gold standard for microvascular imaging, despite the considerable amount of training and optimization needed to properly perfuse the viscous compounds. Even with optimization, frequent gas and water inclusions commonly result in interrupted vessel segments. This lack of suitable compounds has led us to develop the polymeric, cross-linkable X-ray contrast agent XlinCA. As a water-soluble organic molecule, aggregation and inclusions are inherently avoided. High molecular weight allows it to be retained even in the highly fenestrated vasculature of the kidney filtration system. It can be covalently crosslinked using the same aldehydes used in tissue fixation protocols, leading to stable and permanent contrast. These properties allowed us to image whole mice and individual organs in 6 to 12-month-old C57BL/6J mice without requiring lengthy optimizations of injection rates and pressures, while at the same time achieving greatly improved filling of the vasculature compared to resin-based vascular casting. This work aims at illuminating the rationales, processes and challenges involved in creating this recently developed contrast agent.

show abstract

Section: Challenges and Design Considerationsmentioning

confidence: 94%

Section: Methodology 41 Mouse Kidney With Contrast Agent Below the Gl...mentioning

confidence: 99%

Section: Longitudinal Study Of a Mouse Kidney With Non-fixable Contra...mentioning

confidence: 99%

See 1 more Smart Citation

Tomographic imaging of microvasculature with a purpose-designed, polymeric x-ray contrast agent

Kuo

Spingler

et al. 2022

Developments in X-Ray Tomography XIV

Self Cite

View full text Add to dashboard Cite

show abstract

“…Complicating matters, blood does not have to follow the full length of the vasa recta, but may take a shortcut from descending to ascending vasa recta through the peritubular capillary plexus. In general, the intricate three-dimensional vascular organization of the outer medulla adds a layer of complexity to the understanding of shunting mechanisms [ 43 – 45 ].…”

Section: Renal Oxygenationmentioning

confidence: 99%

Renal blood flow and oxygenation

Edwards

Kurtcuoglu

2022

Pflugers Arch - Eur J Physiol

Self Cite

View full text Add to dashboard Cite

Our kidneys receive about one-fifth of the cardiac output at rest and have a low oxygen extraction ratio, but may sustain, under some conditions, hypoxic injuries that might lead to chronic kidney disease. This is due to large regional variations in renal blood flow and oxygenation, which are the prerequisite for some and the consequence of other kidney functions. The concurrent operation of these functions is reliant on a multitude of neuro-hormonal signaling cascades and feedback loops that also include the regulation of renal blood flow and tissue oxygenation. Starting with open questions on regulatory processes and disease mechanisms, we review herein the literature on renal blood flow and oxygenation. We assess the current understanding of renal blood flow regulation, reasons for disparities in oxygen delivery and consumption, and the consequences of disbalance between O2 delivery, consumption, and removal. We further consider methods for measuring and computing blood velocity, flow rate, oxygen partial pressure, and related parameters and point out how limitations of these methods constitute important hurdles in this area of research. We conclude that to obtain an integrated understanding of the relation between renal function and renal blood flow and oxygenation, combined experimental and computational modeling studies will be needed.

show abstract

“…High-resolution nearest-neighborhood analyses of REP cells will be required to statistically evaluate their 3D arrangement relative to specific blood capillary sections and nephron segments. Therefore, we recently reported the combined 3D vascular and tubular imaging of whole mouse kidneys using X-ray μCT [ 60 ]. In a next step, light sheet fluorescence microscopy of the same kidney shall localize tagged REP within the μCT picture.…”

Section: How Do Rep Cells “Sense” Tissue Hypoxia Caused By Decreased ...mentioning

confidence: 99%

Fount, fate, features, and function of renal erythropoietin-producing cells

Dahl

Bapst

Khodo

et al. 2022

Pflugers Arch - Eur J Physiol

Self Cite

View full text Add to dashboard Cite

Renal erythropoietin (Epo)-producing (REP) cells represent a rare and incompletely understood cell type. REP cells are fibroblast-like cells located in close proximity to blood vessels and tubules of the corticomedullary border region. Epo mRNA in REP cells is produced in a pronounced “on–off” mode, showing transient transcriptional bursts upon exposure to hypoxia. In contrast to “ordinary” fibroblasts, REP cells do not proliferate ex vivo, cease to produce Epo, and lose their identity following immortalization and prolonged in vitro culture, consistent with the loss of Epo production following REP cell proliferation during tissue remodelling in chronic kidney disease. Because Epo protein is usually not detectable in kidney tissue, and Epo mRNA is only transiently induced under hypoxic conditions, transgenic mouse models have been developed to permanently label REP cell precursors, active Epo producers, and inactive descendants. Future single-cell analyses of the renal stromal compartment will identify novel characteristic markers of tagged REP cells, which will provide novel insights into the regulation of Epo expression in this unique cell type.

show abstract

Simultaneous Three-Dimensional Vascular and Tubular Imaging of Whole Mouse Kidneys With X-ray μCT

Abstract: Abstract

Cited by 8 publications

References 58 publications

Tomographic imaging of microvasculature with a purpose-designed, polymeric x-ray contrast agent

Tomographic imaging of microvasculature with a purpose-designed, polymeric x-ray contrast agent

Renal blood flow and oxygenation

Fount, fate, features, and function of renal erythropoietin-producing cells

Contact Info

Product

Resources

About