An Isocratic Concurrent Assay of Free Metabolites, 4-Hydroxy-3-methoxy Mandelic Acid, 3-Methoxy-4-hydroxy-phenylglycol, Normetanephrine, Metanephrine, and 5-Hydroxy-Indoleacetic Acid in Same Sample of Urine Extract Using HPLC-ECD

1997 ◽  
Vol 20 (12) ◽  
pp. 1931-1943 ◽  
Author(s):  
Adarsh M. Kumar ◽  
Jesus B. Fernandez ◽  
Karl Goodkin ◽  
Neil Schneiderman ◽  
Carl Eisdorfer
1965 ◽  
Vol 50 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Jürg Müller

ABSTRACT An extract of human urine, which was previously shown to stimulate aldosterone production by rat adrenal sections, was further purified. Evidence was obtained that its aldosterone-stimulating effect was due to the presence of ammonium ions. Addition of ammonium chloride and of urine extract to the incubation medium caused identical increases in aldosterone production in vitro. In addition to ammonium ions, rubidium and caesium ions also stimulated aldosterone production up to 250% that of control values without a significant effect on corticosterone production. Similar dose-response curves were obtained when increasing concentrations of potassium, ammonium, rubidium and caesium ions were tested. Aldosterone production was maximal at concentrations of 7 mval/1 and was significantly lower at higher concentrations. When ammonium chloride and ACTH were simultaneously added to the incubation medium, the production of aldosterone and of corticosterone was lower than with ACTH alone. On the other hand, the stimulating activity on aldosterone and corticosterone production by »TPN« (NADP) and glucose-6-phosphate was enhanced by the simultaneous addition of ammonium chloride.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1131 ◽  
Author(s):  
Federico Di Marco ◽  
Francesco Trevisani ◽  
Pamela Vignolini ◽  
Silvia Urciuoli ◽  
Andrea Salonia ◽  
...  

Pasta is one of the basic foods of the Mediterranean diet and for this reason it was chosen for this study to evaluate its antioxidant properties. Three types of pasta were selected: buckwheat, rye and egg pasta. Qualitative–quantitative characterization analyses were carried out by HPLC-DAD to identify antioxidant compounds. The data showed the presence of carotenoids such as lutein and polyphenols such as indoleacetic acid, (carotenoids from 0.08 to 0.16 mg/100 g, polyphenols from 3.7 to 7.4 mg/100 g). To assess the effect of the detected metabolites, in vitro experimentation was carried out on kidney cells models: HEK-293 and MDCK. Standards of β-carotene, indoleacetic acid and caffeic acid, hydroalcoholic and carotenoid-enriched extracts from samples of pasta were tested in presence of antioxidant agent to determine viability variations. β-carotene and indoleacetic acid standards exerted a protective effect on HEK-293 cells while no effect was detected on MDCK. The concentrations tested are likely in the range of those reached in body after the consumption of a standard pasta meal. Carotenoid-enriched extracts and hydroalcoholic extracts showed different effects, observing rescues for rye pasta hydroalcoholic extract and buckwheat pasta carotenoid-enriched extract, while egg pasta showed milder dose depending effects assuming pro-oxidant behavior at high concentrations. The preliminary results suggest behaviors to be traced back to the whole phytocomplexes respect to single molecules and need further investigations.


2019 ◽  
Vol 361 (15) ◽  
pp. 3560-3568 ◽  
Author(s):  
Benedict Ryan Lukito ◽  
Balaji Sundara Sekar ◽  
Shuke Wu ◽  
Zhi Li
Keyword(s):  

1945 ◽  
Vol 106 (4) ◽  
pp. 420-431 ◽  
Author(s):  
J. M. Beal ◽  
A. Geraldine Whiting

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