Rat kidney brush border enzyme activity following subchronic oral lead exposure

1985 ◽  
Vol 77 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Krystyna Teichert-Kuliszewska ◽  
D.McEwen Nicholls
2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Paulus G. M. Jochems ◽  
Willem R. Keusters ◽  
Antoine H. P. America ◽  
Pascale C. S. Rietveld ◽  
Shanna Bastiaan-Net ◽  
...  

AbstractFood security is under increased pressure due to the ever-growing world population. To tackle this, alternative protein sources need to be evaluated for nutritional value, which requires information on digesta peptide composition in comparison to established protein sources and coupling to biological parameters. Here, a combined experimental and computational approach is presented, which compared seventeen protein sources with cow’s whey protein concentrate (WPC) as the benchmark. In vitro digestion of proteins was followed by proteomics analysis and statistical model-based clustering. Information on digesta peptide composition resulted in 3 cluster groups, primarily driven by the peptide overlap with the benchmark protein WPC. Functional protein data was then incorporated in the computational model after evaluating the effects of eighteen protein digests on intestinal barrier integrity, viability, brush border enzyme activity, and immune parameters using a bioengineered intestine as microphysiological gut system. This resulted in 6 cluster groups. Biological clustering was driven by viability, brush border enzyme activity, and significant differences in immune parameters. Finally, a combination of proteomic and biological efficacy data resulted in 5 clusters groups, driven by a combination of digesta peptide composition and biological effects. The key finding of our holistic approach is that protein source (animal, plant or alternative derived) is not a driving force behind the delivery of bioactive peptides and their biological efficacy.


2017 ◽  
Vol 100 (6) ◽  
pp. 4539-4551 ◽  
Author(s):  
P. Górka ◽  
B.L. Schurmann ◽  
M.E. Walpole ◽  
A. Błońska ◽  
S. Li ◽  
...  

Aquaculture ◽  
2005 ◽  
Vol 248 (1-4) ◽  
pp. 325-335 ◽  
Author(s):  
Sheenan Harpaz ◽  
Yaniv Hakim ◽  
Assaf Barki ◽  
Ilan Karplus ◽  
Tatiyana Slosman ◽  
...  

1988 ◽  
Vol 254 (4) ◽  
pp. F593-F600 ◽  
Author(s):  
R. E. Simmons ◽  
J. T. Hjelle ◽  
C. Mahoney ◽  
L. J. Deftos ◽  
W. Lisker ◽  
...  

The kidneys account for approximately two-thirds of the metabolism of calcitonin, but relatively little is known regarding the details thereof. To further characterize this process, we examined the renal handling and metabolism of human calcitonin (hCT) by the isolated perfused rat kidney. We also studied the degradation of radiolabeled salmon calcitonin (sCT) by subcellular fractions prepared from isolated rabbit proximal tubules. The total renal (organ) clearance of immunoreactive hCT by the isolated kidney was 1.96 +/- 0.18 ml/min. This was independent of the perfusate total calcium concentration from 5.5 to 10.2 mg/dl. Total renal clearance exceeded the glomerular filtration rate (GFR, 0.68 +/- 0.05 ml/min), indicating filtration-independent removal. Urinary calcitonin clearance as a fraction of GFR averaged 2.6%. Gel filtration chromatography of medium from isolated kidneys perfused with 125I-labeled sCT showed the principal degradation products to be low molecular weight forms eluting with monoiodotyrosine. Intermediate size products were not detected. In the subcellular fractionation experiments, when carried out at pH 5.0, calcitonin hydrolysis exclusively followed the activities of the lysosomal enzyme N-acetyl-beta-glucosaminidase. Typically, at pH 7.5, 42% of total degradation occurred in the region of the brush-border enzyme alanyl aminopeptidase and 29% occurred in the region of the cytosolic enzyme phosphoglucomutase. Although 9% of the calcitonin-degrading activity was associated with basolateral membrane fractions, most of this activity could be accounted for by the presence of brush-border membranes.(ABSTRACT TRUNCATED AT 250 WORDS)


1981 ◽  
Vol 193 (3) ◽  
pp. 887-890 ◽  
Author(s):  
H Skovbjerg

The amounts of lactase (beta-D-galactosidase, EC 3.2.1.23), sucrase (sucrose alpha-D-glucohydrolase, EC 3.2.1.48), maltase (alpha-D-glucosidase, EC 3.2.1.20) microvillus aminopeptidase (EC 3.4.11.2) and dipeptidyl peptidase IV (EC 3.4.14.-) in tangentially sectioned biopsies from jejunum were studied by quantitative immunoelectrophoresis and enzymic assays. All enzymes had their maximum activities near the mid-region of the villi and their lowest activities at the bases of the crypts. The ratio between enzyme activity and immunoreactive protein was constant along the villus-crypt axis. This result is consistent with a continuous brush-border-enzyme synthesis as the enterocytes migrate up the villi.


2007 ◽  
Vol 48 (6) ◽  
pp. 696-702 ◽  
Author(s):  
E. Rueda ◽  
M. León ◽  
M. Castañeda ◽  
A. Mendez ◽  
C. Michelangeli

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