Effect of Urine pH, Storage Time, and Temperature on Stability of Catecholamines, Cortisol, and Creatinine

Miki, Keiichi; Sudo, Ayako

doi:10.1093/clinchem/44.8.1759

Cited by 80 publications

(33 citation statements)

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“…In both studies, storage at -20 ∞ C appeared least favourable both due to a higher degradation rate and the formation of a calciumphosphate precipitate that was observed at this specific temperature. 22,23 The adjustment of pH prior to freezing did not appear to affect protein stability. 23…”

Section: Collection Processing and Storage Of Urinary Samplesmentioning

confidence: 97%

“…With regard to the degradation of frozen proteins over time, evidence from previous studies suggests that there is considerable interprotein variation in the degree of degradation. 22,23 Furthermore, these studies concluded that if urinary proteins can be measured within 4 weeks after sampling, storage at 4 ∞ C appears to give the best results. It may be desirable to add biocides such as sodium azide or thymol.…”

Section: Collection Processing and Storage Of Urinary Samplesmentioning

confidence: 99%

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Prospects for urinary proteomics: Exosomes as a source of urinary biomarkers (Review Article)

et al. 2005

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SUMMARY:Recent progress in biotechnology offers the promise of better medical care at lower costs. Among the techniques that show the greatest promise is mass spectrometry of proteins, which can identify proteins present in body fluids and tissue specimens at a large scale. Because urine can be collected in large amounts in a non-invasive fashion, the potential exists to use mass spectrometry to discover urinary biomarkers that are early predictors of renal disease, or useful in making therapeutic choices. Recently, the authors demonstrated that both membrane proteins and cytosolic proteins from renal epithelia are highly enriched in low-density urinary structures identified as exosomes. Exosomes were found to contain many disease-associated proteins including aquaporin-2, polycystin-1, podocin, non-muscle myosin II, angiotensin-converting enzyme, Na-cotransporter (NKCC2), thiazide-sensitive Na-Cl cotransporter (NCC), and epithelial sodium channel (ENaC). Potentially, other disease biomarkers could be discovered by mass spectrometry-based proteomic studies in well-defined patient populations. Herein is described the advantages of using urinary exosomes as a starting material for biomarker discovery. In addition, the purpose of this review is to present an overall strategy for biomarker discovery in urine using exosomes and for developing costeffective clinical assays for these biomarkers, which can potentially be used for early detection of disease, as a means of differential diagnosis, or as a means of guiding therapy. Finally, potential barriers that need to be overcome before urinary proteomics can be applied clinically, are emphasized.

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Section: Collection Processing and Storage Of Urinary Samplesmentioning

confidence: 97%

Section: Collection Processing and Storage Of Urinary Samplesmentioning

confidence: 99%

Prospects for urinary proteomics: Exosomes as a source of urinary biomarkers (Review Article)

et al. 2005

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“…Large epidemiological samples, including the National Collaborative Perinatal Project (NCPP), in which blood/serum was collected during pregnancy and offspring were followed longitudinally, offer the unique opportunity to examine links between prenatal exposure to steroid hormones and long-term offspring outcomes. However, although steroid hormones are believed to be some of the most stable and resilient molecules to variations in storage duration and conditions (Kley and Rick, 1984;Miki and Sudo, 1998;Garde and Hansen, 2005), the validity of prenatal levels of steroid hormones after decades of storage has not been determined. As cortisol and testosterone have been proposed as key mediators of prenatal "programming," we examined stability of concentrations of maternal cortisol and testosterone and their binding globulins (cortisol binding globulins (CBG) and sex hormone binding globulin (SHBG)) after more than forty years of storage.…”

Section: Introductionmentioning

confidence: 99%

Long-term stability of maternal prenatal steroid hormones from the National Collaborative Perinatal Project: Still valid after all these years

Stroud

Solomon

Shenassa

et al. 2007

Psychoneuroendocrinology

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Large epidemiological samples, including the National Collaborative Perinatal Project (NCPP), in which blood/serum was collected during pregnancy and offspring followed longitudinally, offer the unique opportunity to examine neuroendocrine mechanisms underlying prenatal "programming" of adult health and disease. However, in order to conduct longitudinal analyses, it is critical to determine the validity of maternal prenatal samples stored over long periods. We investigated the validity of cortisol, testosterone, and their binding globulins (corticosteroid-binding globulin (CBG) and sex hormone-binding globulin (SHBG)) in maternal prenatal serum from the NCPP after over 40 years of storage. Study 1 included 64 maternal serum samples collected on the day of delivery; study 2 involved 1099 third trimester serum samples collected between gestational weeks 31 and 36. Across both studies, cortisol and testosterone concentrations were consistent with values from published studies of fresh samples collected at similar points in gestation. CBG and SHBG were present, but showed some differences from published studies. Results support the validity of cortisol and testosterone values following 40+ years of storage. Results also provide validation for future longitudinal tests of prenatal "programming" hypotheses within the NCPP. Stability of steroid hormones over decades suggests that stored samples from other longitudinal studies may also allow opportunities to investigate links between prenatal steroids and long-term offspring outcomes.

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“…NE and DA extraction was accomplished following the manufacturer's instructions (Labor Diagnostika Nord). Urine samples were not acidified as a recent study has indicated that urine pH has no substantial effect on the stability of the catecholamines [67]. Each catecholamine was measured independently on separate plates from one pretreated aliquot of the sample.…”

Section: Methodsmentioning

confidence: 99%

Emotional States of Love Moderate the Association Between Catecholamines and Female Sexual Responses in the Laboratory

Dundon

Rellini

2012

The Journal of Sexual Medicine

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Introduction Research suggests that there are three interrelated, yet distinct, emotion motivation brain systems for human love (lust, romantic love, and attachment), each associated with a unique catecholaminergic and hormonal profile. Of interest for the current study are norepinephrine (NE) and dopamine (DA), which have a hypothesized connection with romantic love. As NE and DA are also known to facilitate sexual arousal, it is plausible that NE and DA may have a greater positive association with the sexual arousal responses of women in romantic love compared with women in lust. Aim This study investigated if the effects of NE and DA activity on sexual arousal responses would differ depending on emotion motivation state (Lust or Romantic). Main Outcome Measures Physiological sexual arousal was assessed by photoplethysmography and subjective sexual arousal was assessed with a participant controlled lever. Methods Seventeen women were included in the Lust group and 29 in the Romantic group. All participants provided a urine sample (to assess NE and DA) and completed a psychophysiological assessment. Results Elevated NE was positively and significantly associated with greater subjective and physiological sexual arousal for the Lust group, but not for the Romantic group. Similarly, elevated DA was positively and significantly associated with greater subjective sexual arousal for the Lust group, but not for the Romantic group. Conclusions The sexual arousal responses of women in the Lust group, but not in the Romantic group, were positively and significantly associated with elevated NE and DA. It is feasible that, when women are seeking a partner (Lust), NE and DA may facilitate attention toward sexually relevant stimuli.

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Effect of Urine pH, Storage Time, and Temperature on Stability of Catecholamines, Cortisol, and Creatinine

Cited by 80 publications

References 5 publications

Prospects for urinary proteomics: Exosomes as a source of urinary biomarkers (Review Article)

Prospects for urinary proteomics: Exosomes as a source of urinary biomarkers (Review Article)

Long-term stability of maternal prenatal steroid hormones from the National Collaborative Perinatal Project: Still valid after all these years

Emotional States of Love Moderate the Association Between Catecholamines and Female Sexual Responses in the Laboratory

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