scholarly journals GC-MS Studies on Derivatization of Creatinine and Creatine by BSTFA and Their Measurement in Human Urine

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3206
Author(s):  
Olga Begou ◽  
Kathrin Weber ◽  
Bibiana Beckmann ◽  
Dimitrios Tsikas
Keyword(s):  
Urinary Excretion ◽  
Human Urine ◽  
Chemical Ionization ◽  
Excretion Rate ◽  
Internal Standard ◽  
Negative Ion ◽  
Reaction Products ◽  
Urinary Excretion Rate ◽  
Selected Ion Monitoring ◽  
Keto Form

In consideration of its relatively constant urinary excretion rate, creatinine (2-amino-1-methyl-5H-imidazol-4-one, MW 113.1) in urine is a useful endogenous biochemical parameter to correct the urinary excretion rate of numerous endogenous and exogenous substances. Reliable measurement of creatinine by gas chromatography (GC)-based methods requires derivatization of its amine and keto groups. Creatinine exists in equilibrium with its open form creatine (methylguanidoacetic acid, MW 131.1), which has a guanidine and a carboxylic group. Trimethylsilylation and trifluoroacetylation of creatinine and creatine are the oldest reported derivatization methods for their GC-mass spectrometry (MS) analysis in human serum using flame- or electron-ionization. We performed GC-MS studies on the derivatization of creatinine (d0-creatinine), [methylo-2H3]creatinine (d3-creatinine, internal standard) and creatine (d0-creatine) with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) using standard derivatization conditions (60 min, 60 °C), yet in the absence of any base. Reaction products were characterized both in the negative-ion chemical ionization (NICI) and in the positive-ion chemical ionization (PICI) mode. Creatinine and creatine reacted with BSTFA to form several derivatives. Their early eluting N,N,O-tris(trimethylsilyl) derivatives (8.9 min) were found to be useful for the precise and accurate measurement of the sum of creatinine and creatine in human urine (10 µL, up to 20 mM) by selected-ion monitoring (SIM) of m/z 271 (d0-creatinine/d0-creatine) and m/z 274 (d3-creatinine) in the NICI mode. In the PICI mode, SIM of m/z 256, m/z 259, m/z 272 and m/z 275 was performed. BSTFA derivatization of d0-creatine from a freshly prepared solution in distilled water resulted in formation of two lMate-eluting derivatives (14.08 min, 14.72 min), presumably creatinyl-creatinine, with the creatininyl residue existing in its enol form (14.08 min) and keto form (14.72 min). Our results suggest that BSTFA derivatization does not allow specific analysis of creatine and creatinine by GC-MS. Preliminary analyses suggest that pentafluoropropionic anhydride (PFPA) is also not useful for the measurement of creatinine in the presence of creatine. Both BSTFA and PFPA facilitate the conversion of creatine to creatinine. Specific measurement of creatinine in urine is possible by using pentafluorobenzyl bromide in aqueous acetone.

Direct Proportionality of Urinary Excretion Rate and Serum Level of Tetracycline in Human Subjects

Nature ◽  
1963 ◽  
Vol 198 (4879) ◽  
pp. 450-453 ◽  
Author(s):  
T. CHULSKI ◽  
R. H. JOHNSON ◽  
C. A. SCHLAGEL ◽  
J. G. WAGNER
Keyword(s):  
Serum Level ◽  
Urinary Excretion ◽  
Excretion Rate ◽  
Human Subjects ◽  
Urinary Excretion Rate ◽  
Direct Proportionality

Compartmental transfer of mercury released from amalgam

1997 ◽  
Vol 16 (11) ◽  
pp. 667-672 ◽  
Author(s):  
S. Halbach ◽  
L. Kremers ◽  
H. Willruth ◽  
A. Mehl ◽  
G. Welzl ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Urinary Excretion ◽  
Total Mercury ◽  
Excretion Rate ◽  
Absorbed Dose ◽  
Correlation Coefficients ◽  
Urinary Excretion Rate ◽  
Amalgam Fillings

The number of amalgam-covered surfaces and the occlusal area of the fillings, the concentrations of total mercury in plasma, erythrocytes and urine, the urinary excretion rate, and the absorbed daily doses estimated by two separate methods from intra-oral Hg emission were determined in 29 volunteers with a low amalgam load. The transfer ofHg from the fillings via the oral cavity and blood to urinary excretion was evaluated by multiple correla tions between these variables. In addition, the combina tion of variables most representative of the entire compartmental transfer of amalgam Hg was determined. Urinary excretion (1), Hg concentration in plasma (2) and absorbed dose (3) were most closely correlated to each other, followed by correlations with the variables of the fillings (4). Correlation coefficients were 0.75 for variables 1 vs 2 and 2 vs 3, and 0.49 for variables 3 vs 4. It was concluded that variables 1-3 best reflected the transfer of mercury from amalgam fillings throughout the organism and that they were relatively insensitive to dietary mercury. The determination of total mercury in plasma and of its urinary excretion rate appears, under practical aspects, most suitable for the investigation of Hg uptake from amalgam.

scholarly journals Pregnancy Enhances the Angiotensin (Ang)-(1–7) Vasodilator Response in Mesenteric Arteries and Increases the Renal Concentration and Urinary Excretion of Ang-(1–7)

Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3338-3343 ◽  
Author(s):  
Liomar A. A. Neves ◽  
Aleck F. Williams ◽  
David B. Averill ◽  
Carlos M. Ferrario ◽  
Michael P. Walkup ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Excretion Rate ◽  
Virgin Female ◽  
Cardiovascular Regulation ◽  
Mesenteric Arteries ◽  
Female Rats ◽  
Resistance Arteries ◽  
Urinary Excretion Rate ◽  
Response Curves ◽  
Mesenteric Vessels

Abstract The vasoactive effect of angiotensin (Ang)-(1–7) in mesenteric resistance arteries together with its plasma and kidney concentration and urinary excretion was assessed in pregnant and virgin rats. Mesenteric arteries (230–290 μm) were mounted in a pressurized myograph system and Ang-(1–7) concentration-dependent response curves (10−10–10−5m) were determined in arteries preconstricted with endothelin-1 (10−7m). The Ang-(1–7) response was investigated in vessels with and without pretreatment with the Ang-(1–7) antagonist [d-[Ala7]-Ang-(1–7)] (10−7m). Ang-(1–7) caused a significantly enhanced, concentration-dependent dilation of mesenteric vessels (EC50 = 2.7 nm) from pregnant compared with virgin female rats. d-[Ala7]-Ang-(1–7) eliminated the vasodilator effect of Ang-(1–7). There was no significant change in plasma concentration of Ang-(1–7) in pregnant animals. On the other hand, 24 h urinary excretion and kidney concentration of Ang-(1–7) were significantly higher in pregnant animals. The increased mesenteric dilation to Ang-(1–7) with enhanced kidney concentration and 24 h urinary excretion rate of Ang-(1–7) suggests an important role for this peptide in cardiovascular regulation during pregnancy.

Functional significance of exaggerated renal thromboxane A2 synthesis induced by cyclosporin A

1986 ◽  
Vol 251 (4) ◽  
pp. F581-F587 ◽  
Author(s):  
N. Perico ◽  
A. Benigni ◽  
C. Zoja ◽  
F. Delaini ◽  
G. Remuzzi
Keyword(s):  
Urinary Excretion ◽  
Cyclosporin A ◽  
Chronic Treatment ◽  
Excretion Rate ◽  
Thromboxane A2 ◽  
Significant Negative Correlation ◽  
Progressive Increase ◽  
Urinary Excretion Rate ◽  
Acid Clearance ◽  
Selective Increase

Animals and humans undergoing a chronic treatment with cyclosporin A (CyA) show a reduction in glomerular filtration rate (GFR). The cause of this abnormality has not been established. Since CyA interferes with arachidonic acid (AA) metabolism in various cells, we wished to determine whether alterations in renal AA metabolites contribute to deteriorating renal function in rats on CyA. We show that chronic CyA treatment induces a progressive increase in the renal synthesis of thromboxane (TX) A2. This is a selective abnormality in that CyA does not influence the renal synthesis of prostaglandin E2 (PGE2) and prostacyclin (PGI2). A significant negative correlation has been found between TXB2 urinary excretion rate and inulin clearance. No correlation has been observed between TXB2 excretion and p-aminohippuric acid clearance. The withdrawal of CyA is followed by a normalization of both TXB2 urinary excretion rate and GFR. The administration of a selective TXA2 inhibitor, UK-38,485, resulted in a significant reduction in urinary excretion of TXB2 accompanied by a significant increase in GFR. We conclude that chronic treatment with CyA in rats is associated with a selective increase in renal TXA2 synthesis and suggest that this abnormality may play a role in the reduction of GFR.

Urinary Excretion Rate of Guanidinoacetic Acid in Essential Hypertension

Guanidines 2 ◽  
1989 ◽  
pp. 137-146
Author(s):  
Yoshiyuki Takano ◽  
Fumitake Gejyo ◽  
Yoshio Shirokane ◽  
Moto-o Nakajima ◽  
Masaaki Arakawa
Keyword(s):  
Essential Hypertension ◽  
Urinary Excretion ◽  
Excretion Rate ◽  
Urinary Excretion Rate ◽  
Guanidinoacetic Acid

Abstract 042: Effects of Diuretics on Sglt2 Inhibitor-induced Changes in Urinary Sodium Excretion Rate In Obese Metabolic Syndrome Rats

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
AKIRA NISHIYAMA ◽  
Yoshihide Fujisawa ◽  
Abu Sufiun ◽  
Kazi Rafiq ◽  
Daisuke Nakano ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Glucose Metabolism ◽  
Urinary Excretion ◽  
Excretion Rate ◽  
Sglt2 Inhibitor ◽  
Urinary Sodium Excretion ◽  
Sglt2 Inhibitors ◽  
Urinary Sodium ◽  
Urinary Excretion Rate ◽  
Induced Changes

Proximal tubular sodium-glucose co-transporter 2 (SGLT2) transports glucose and sodium with a 1:1 stoichiometry. However, studies have indicated that treatment with SGLT2 inhibitors does not substantially increase the urinary excretion rate of sodium, while that of glucose is markedly increased. These data suggest that urinary sodium is reabsorbed by other mechanisms distal to the nephron during SGLT2 inhibition. Here, we aimed to investigate whether diuretics affect the SGLT2 inhibitor-induced changes in the urinary excretion rate of sodium in obese metabolic syndrome SHR/NDmcr-cp(+/+) (SHRcp) rats. Male 13-week-old SHRcp rats were treated with: 1) vehicle (0.5% carboxymethylcellulose), 2) a SGLT2 inhibitor, luseogliflozin (10 mg/kg/day, p.o.), 3) luseogliflozin + hydrochlorothiazide (10 mg/kg/day, p.o.) or 4) luseogliflozin + hydrochlorothiazide + furosemide (5 mg/kg/day, p.o.) for 5 weeks (n = 6-8 per group). Blood pressure and glucose metabolism were evaluated by telemetry and oral glucose tolerance test respectively. Vehicle-treated SHRcp rats developed non-dipper type hypertension (night and day time systolic blood pressure; 186 ± 2 and 185 ± 2 mmHg, respectively) and insulin resistance. As compared with vehicle-treated animals, luseogliflozin-treated rats showed an approximately 4,000-fold increase in urinary glucose excretion and improved glucose metabolism. Luseogliflozin also slightly decreased blood pressure, which was associated with an approximately 30% increase in urinary excretion of sodium. The addition of hydrochlorothiazide or hydrochlorothiazide + furosemide further decreased blood pressure and improved blood pressure circadian rhythm to a dipper profile in luseogliflozin-treated animals. In these animals, urinary sodium excretion tended to be increased by diuretics, although these changes were not statistically significant. These data indicate that SGLT2 inhibitor-induced natriuresis is not enhanced by diuretics. Thus, SGLT2 inhibitors may elicit their beneficial effects on glucose metabolism and hypertension in patients who are treated with diuretics.

Can urinary excretion rate of 8-isoprostrane and malonaldehyde predict postoperative cognitive dysfunction in aging?

2013 ◽  
Vol 34 (9) ◽  
pp. 1665-1669 ◽  
Author(s):  
Qinghao Cheng ◽  
Jiawan Wang ◽  
Anshi Wu ◽  
Rujin Zhang ◽  
Lei Li ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Cognitive Dysfunction ◽  
Excretion Rate ◽  
Postoperative Cognitive Dysfunction ◽  
Urinary Excretion Rate

Urinary excretion rate of ceruloplasmin in non-insulin-dependent diabetic patients with different stages of nephropathy

1995 ◽  
Vol 132 (6) ◽  
pp. 681-687 ◽  
Author(s):  
Masatoshi Yamazaki ◽  
Seiki Ito ◽  
Akio Usami ◽  
Nagayuki Tani ◽  
Osamu Hanyu ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Excretion Rate ◽  
University Hospital ◽  
Tubular Function ◽  
Dependent Diabetes Mellitus ◽  
Diabetic Patients ◽  
Urinary Excretion Rate ◽  
Serum Samples ◽  
Insulin Dependent ◽  
Insulin Dependent Diabetic

Yamazaki M, Ito S, Usami A, Tani N, Hanyu 0, Nakagawa O. Nakamura H, Shibata A. Urinary excretion rate of ceruloplasmin in non-insulin-dependent diabetic patients with different stages of nephropathy. Eur J Endocrinol 1995;132:681–7. ISSN 0804–4643 The level of ceruloplasmin, which is a more negatively charged protein than albumin, was measured by an immunoradiometric assay in timed overnight urine and serum samples from patients with non-insulin-dependent diabetes mellitus and healthy controls. None of the plasma proteins examined showed any cross-reactivity in this assay. A linear correlation was seen between the ceruloplasmin level and the serial dilution of the sample. Western blot analysis using concentrated urine samples showed that the molecular weight of ceruloplasmin in the urine sample was the same as that of ceruloplasmin in the serum and standard samples. These findings indicated that the substance detected by this assay was truly ceruloplasmin. The urinary ceruloplasmin excretion rate (CER) and clearance of ceruloplasmin increased in parallel with the progression of albuminuria. The highest CER was found in macroalbuminuric patients, followed by micro- and normoalbuminuric patients and the healthy control subjects, the differences between the groups being significant. In view of the fact that the isoelectric point of ceruloplasmin (4.4) is more acidic than that of albumin, the present findings suggested that an enhanced CER was due either to the alteration of charge selectivity in the glomerular basement membrane with unaltered tubular function or to a defect of the non-discriminatory pores (shunt pathway) with unaltered tubular function. Seiki Ito, Division of Gerontology, Akita University Hospital, 1-1-1 Hondou, Akita City, Japan 010

Sign in / Sign up

Export Citation Format

Share Document