Pineal and plasma melatonin as determined by high-performance liquid chromatography with electrochemical detection

Vieira, Raúl; Míguez, Jesús M.; Lema, M; Aldegunde, M.

doi:10.1016/0003-2697(92)90439-e

Cited by 56 publications

(35 citation statements)

References 10 publications

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“…Epinephrine and norepinephrine levels were determined by means of high-performance liquid chromatography (HPLC) and electrochemical detection after liquid-liquid extraction (Ehrenreich et al 1997). Melatonin was extracted with methylene chloride and analysed with a reversed phase HPLC with fluorescence detection (Vieira et al 1992). The lower limit of detection (LOD) for the melatonin concentration was 2.5 pg/mL.…”

Section: Design and Proceduresmentioning

confidence: 99%

Melatonin improves memory acquisition under stress independent of stress hormone release

et al. 2008

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Rationale: Animal studies suggest that the pineal hormone melatonin influences basal stress hormone levels and dampens hormone reactivity to stress. Objectives: We investigated whether melatonin also has a suppressive effect on stress-induced catecholamine and cortisol release in humans. As stress hormones affect memory processing, we further examined a possible accompanying modulation of memory function. Methods: Fifty healthy young men received a single oral dose of either 3mg melatonin (n = 27) or placebo medication (n = 23).One hour later, they were exposed to a standardized psychosocial laboratory stressor (Trier Social Stress Test). During stress, subjects encoded objects distributed in the test room, for which memory was assessed a day later ("memory encoding under stress"). 15 min following stress, memory retrieval for words learnt the day before was tested ("memory retrieval after stress"). Plasma epinephrine and norepinephrine levels, salivary free cortisol levels, and psychological responses (attention, wakefulness) were repeatedly measured before and after stress exposure. Results: Melatonin specifically enhanced recognition memory accuracy of objects encoded under stress (p <.001). In contrast, 15 min after stress, when cortisol levels were highest, retrieval of memories acquired the day before was not influenced by melatonin.Moreover, melatonin did not influence stress-induced elevation of catecholamine and cortisol levels which in turn did not correlate with the effects of melatonin on memory. Conclusions:The findings point to a primary action of melatonin on central nervous stimulus processing under conditions of stress, and possibly on memory consolidation, and exclude any substantial suppressive action of the substance on hormonal stress responses.

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Section: Design and Proceduresmentioning

confidence: 99%

Melatonin improves memory acquisition under stress independent of stress hormone release

et al. 2008

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“…In these methods, a high concentration of organic solvents, such as 20 -50% of MeOH or MeCN, was required as the mobile phase. [25][26][27]29,30 However, melatonin could not be oxidized in these mobile phases containing a high concentration of organic solvents.…”

Section: Effect Of Organic Solvents On the Oxidation Of Melatonin Andmentioning

confidence: 98%

“…Until now, various analytical methods, such as enzyme immunoassay, [18][19][20][21]28 GC-MS [22][23][24] and HPLC methods, [25][26][27]29,30 have been reported for the determination of melatonin. Enzymatic methods (both RIA and ELISA) are frequently used, and various assay kits are commercially available.…”

Section: Development Of a Fully-automated On-line Oxidation Columnswimentioning

confidence: 99%

“…However, the amount of endogenous melatonin is extremely low, and a 1 -5 mL blood sample is needed for the determination of melatonin by the methods already reported. [17][18][19][20][21][22][23][24][25][26][27] To obtain 1 -5 mL of blood, blood sampling from the cubital vein is normally required, and it is practically a severe task for patients to measure the circadian rhythm of melatonin (blood should be obtained 6 -8 times within one day). Therefore, a highly sensitive and selective analytical method, which can determine endogenous melatonin using 10 -100 μL of plasma (100 μL of plasma can be obtained by a less invasive method) is required.…”

Section: Introductionmentioning

confidence: 99%

“…Radioimmunoassay (RIA), [18][19][20] enzyme-linked immunosorbent assay (ELISA), 21,28 gas chromatography (GC) [22][23][24] and high-performance liquid chromatography (HPLC) [25][26][27]29,30 are frequently used. The melatonin rhythm in human plasma/serum and saliva has also been studied using these methods, and the amounts of melatonin are reported to be 3 to 10 pM in the diurnal period.…”

Section: Introductionmentioning

confidence: 99%

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Development of a Fully-automated On-line Oxidation Column-switching HPLC System for the Determination of Endogenous Melatonin in Human Clinical Samples

et al. 2015

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A fully-automated on-line oxidation column-switching HPLC system has been developed for the determination of endogenous melatonin in human plasma and saliva. This HPLC system consists of four processes. In the first step, melatonin is fractionated using a reversed-phase C4 column (Proteonavi, 75 mm × 1.0 mm i.d.). In the second step, the obtained melatonin fraction is on-line collected, and oxidized to a highly-fluorescent compound, N- [(6-methoxy-4-oxo-1,4-dihydroquinolin-3-yl)methyl]acetamide (6-MOQMA), by mixing with hydrogen peroxide under alkaline conditions. In the third step, the produced 6-MOQMA is concentrated, and the oxidation reagents are removed using an alkaline resistive reversed-phase column, Asahipak ODP (35 mm × 1.0 mm i.d.). In the final fourth step, the 6-MOQMA is determined by a microbore-ODS column packed with ultrafine particles (CAPCELL PAK C18 IF, 250 mm × 1.0 mm i.d.). The limit of detection of melatonin using this system is about 200 amol/injection, and the determination of endogenous melatonin in a small volume of human physiological fluids, such as 100 μL of plasma and 300 μL of saliva, was successfully accomplished.

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Effects of melatonin on dopamine metabolism in the hypothalamus and the pituitary of the rainbow trout,Oncorhynchus mykiss

Hernandez-Rauda¹,

Míguez²,

Ruibal³

et al. 2000

J. Exp. Zool.

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Pineal and plasma melatonin as determined by high-performance liquid chromatography with electrochemical detection

Cited by 56 publications

References 10 publications

Melatonin improves memory acquisition under stress independent of stress hormone release

Melatonin improves memory acquisition under stress independent of stress hormone release

Development of a Fully-automated On-line Oxidation Column-switching HPLC System for the Determination of Endogenous Melatonin in Human Clinical Samples

Effects of melatonin on dopamine metabolism in the hypothalamus and the pituitary of the rainbow trout,Oncorhynchus mykiss

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