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Kinetics and Metabolism
Published in Lars Friberg, Tord Kjellström, Carl-Gustaf Elinder, Gunnar F. Nordberg, Cadmium and Health: A Toxicological and Epidemiological Appraisal, 2019
Gunnar F. Nordberg, Tord Kjellström, Monica Nordberg
Gunn and Gould104 gave a single intracardiac injection of 115Cd nitrate to rats (dose not stated) and studied the animals for up to 8 months. Shortly after exposure, the highest concentration was seen in the liver (Figure 15). During the first month there was a decrease in liver levels of 115Cd and an increase in kidney cortex levels, so that a month after exposure the concentration in the cortex was the same as that in the liver (Figure 15). During the following months liver levels decreased very slowly, while levels in renal cortex increased so that after 5 months the ratio between renal cortex and liver levels was about 2 and after 8 months it was about 4. The levels in kidney medulla also increased with time (Figure 15).
The Microenvironment in Multicellular Spheroids
Published in Rolf Bjerkvig, Spheroid Culture in Cancer Research, 2017
The simultaneous occurrence of oxygen consumption and lactate production is reminiscent of the original ideas of Warburg,24 i.e., that aerobic glycolysis takes place in the metabolism of tumor cells and might be one step towards, or as a result of, the transformation to malignancy. Normal tissues from retina, kidney-medulla, and fetal tissue have, however, this property without any signs of pathologic growth control.25 Thus, lactate production under normoxic conditions is not a unique characteristic of malignancy.
CEST Contrast Agents
Published in Martin G. Pomper, Juri G. Gelovani, Benjamin Tsui, Kathleen Gabrielson, Richard Wahl, S. Sam Gambhir, Jeff Bulte, Raymond Gibson, William C. Eckelman, Molecular Imaging in Oncology, 2008
Jason M. Zhao, Assaf A. Gilad, Michael T. McMahon, Jeff W. M. Bulte, Peter C. M. van Zijl
Guivel-Scharen et al. carefully addressed these challenges and were able to obtain MTRasy spectra of various rabbit tissues ex vivo (45). In particular, they found a large 10% MTRasy for rabbit kidney medulla between a chemical shift of 1.0 and 2.6 ppm. This effect could be attributed to small nitrogen-containing molecules in urine such as urea and ammonia. As a final proof of principle, the authors imaged whole rabbit kidney ex vivo with a presaturation pulse at 1.74 ppm at 11.7 T and observed hypointensity in the medulla region in the difference image with and without the presaturation pulse.
Renal involvement in paroxysmal nocturnal hemoglobinuria: an update on clinical features, pathophysiology and treatment
Published in Hematology, 2018
Styliani I Kokoris, Eleni Gavriilaki, Aggeliki Miari, Αnthi Travlou, Elias Kyriakou, Achilles Anagnostopoulos, Elissavet Grouzi
Nitric oxide (NO) is the main regulator of vascular tone. Normal levels of NO lead to the dilatation of blood vessels and to increased blood flow [59]. During intense hemolysis, erythrocytes release arginase in plasma. Arginase converts l-arginine into ornithine, thus reducing the primary source of NO production and synthesis. The accumulation of free hemoglobin in the plasma dramatically reduces the levels of NO (NO scavenging). NO reacts irreversibly with free hemoglobin and produces NO3 and methemoglobin. The reduction of NO, due to its binding with heme, leads to vasoconstriction, which is most pronounced in the kidney medulla. The above phenomenon results in a reduction of blood flow to the kidneys causing severe and prolonged hypoxia which ultimately leads to tubular necrosis [60]. The reduction of NO may also result in a diminished activation of the soluble cytosolic guanylate cyclase (sGC) and decreased cGMP (cyclic Guanosine Monophosphate) levels, that disrupt the regulation of smooth muscle tone causing dystonias (with multiple subsequent symptoms), like systemic and pulmonary hypertension, dysphagia, esophageal spasm, retrosternal pain, atypical abdominal pain and erectile dysfunction (mainly in hemolytic crisis). Decreased cGMP levels can also lead to platelets activation and aggregation, promoting clot formation [61].
Enalapril decreases rat plasma concentration of TMAO, a gut bacteria-derived cardiovascular marker
Published in Biomarkers, 2018
Marek Konop, Marek Radkowski, Marta Grochowska, Karol Perlejewski, Emilia Samborowska, Marcin Ufnal
ACE-Is such as enalapril, have been found to reduce cardiovascular risk. The beneficial effects of ACE-I are thought to be caused by the inhibition of the renin–angiotensin–aldosterone system effects on arterial blood pressure, the vasculature, heart and the kidneys, including decreased sodium reabsorption by the kidneys (Ferrario and Mullick 2017). Accordingly, we found that rats treated with enalapril showed an increased 24 hr urine excretion of sodium. This was associated with lower sodium and TMAO plasma levels and higher 24 hr urine excretion of sodium. Therefore, it may be hypothesized that TMAO and sodium plasma levels are regulated by a common mechanism controlling either the excretion or distribution of both solutes. In this regard, there is ample evidence for a positive correlation between sodium and trimethylamines tissue level. For example, animals that live in saltwater accumulate TMAO, and use it as an osmolyte which protects cell against osmotic stress (Yancey 2005). Similarly, in mammals the accumulation of methylamines in the kidney medulla protects renal cells from hyperosmotic environment resulting from high concentrations of sodium and urea (Somero 1986).
Oral administration of oxalate-enriched spinach extract as an improved methodology for the induction of dietary hyperoxaluric nephrocalcinosis in experimental rats
Published in Toxicology Mechanisms and Methods, 2018
Abhishek Albert, Vidhi Tiwari, Eldho Paul, Sasikumar Ponnusamy, Divya Ganesan, Rajkumar Prabhakaran, Selvi Mariaraj Sivakumar, Selvam Govindan Sadasivam
Oxalate and calcium content in kidney homogenates of group II, III and V rats were significantly increased (p < .05) when compared to group I control (Table 5). However, higher oxalate content was recorded in kidney homogenates of group II and III rats compared to spinach extract administered group V rats (p< .05). A mild to moderate triaditis and Kupffer cell hyperplasia was observed in liver sections of group II and III rats. No evidence of vascular congestion, necrosis or fibrosis was noticed in group I, IV and V rats (Figure 5(A–E)). Histopathological assessment of EG and KOx administered rat kidneys revealed marked glomerular atrophy, severe interstitial inflammation and extensive region of red blood casts. Spinach extract administered rat kidney sections showed slight glomeruli and tubular lesions with mild interstitial lymphatic infiltration whereas no remarkable changes were observed in group I rats (Figure 6(A–E)). The aggregation of crystal was noticed in the cortex and tubules of kidney medulla in group II, III and V rats. The birefringence property of crystal deposits were observed by polarized light microscopy (Figure 6(G–J)). Pizzaloto staining results showed CaOx crystallization in paraffin-embedded kidney sections of group II, III and V rats (Figure 6(L–O)). On the contrary, no evidence of CaOx crystal aggregation was observed in group I rats (Figure 6(F,K)).