Anonymous asked in 社會與文化語言 · 1 decade ago


The determination of urinary electrolytes is helpful in the

diagnosis of children with certain diseases such as dyselectrolytemia

or metabolic acid–base imbalance of unknown origin

[1]. Diurnal variations of urinary solute excretion have been

reported in children, but few data dealing with chronobiological

aspects are available [2–7]. We found worth studying the

circadian rhythm of urinary variables with the aim to establish

circadian reference values in prepubertal boys. We therefore

examined the 24-h urinary excretion of a set of routinely

determined variables: electrolytes (calcium, magnesium, and

phosphorus), urea, and creatinine in urine of voluntary healthy

prepubertal boys.

Nine healthy prepubertal (Tanner stage I) boys aged 10.8±0.11

years, attending the same junior school and the same classroom,

were enrolled into the study (Table 1). All had normal growth

parameters and close weight, height, and bodymass index, had no

known medical illnesses or endocrine dysfunction and were not

receivingmedications. The children of this study were comparable

and had roughly the same synchronization (time to bed and time

awake), the same type of diet (quality and quantity) and mainly

drank water with one to two sodas per day. Parental consent and

children's assent were obtained before entry into the study. The

study was approved by the Review Board of the Institute and

performed in agreement with the Standards and Ethics in

Biological Rhythm Research [8].

The subjects were admitted on a weekend during spring, after

the class for 24 h at the same location (at home of the first author)

in Paris, France. Subjects were required to be in bed with the

roomlights turned off from21:00 h±30 min to 07:00 h±30 min, a

schedule close to their usual synchronisation. Meals were provided

at 07:30 h±30 min, 12:00 h±30 min and 20:00 h±30 min.

To standardize the experimental conditions in regards to posture

and physical activity, children rested about 30min during daytime

before each sampling.


Total urine voidings were collected during nine consecutive 3-h periods.

Urine sampleswere stored at −20 °C until processed.

Biochemical determinations of urinary solutes have been described previously [9].

Update 2:

The assays for each variable were done in a single series to avoid analytical variations between assays.

Calcium was determined using a cresolphthalein method (Biomérieux kit, France).

Magnesium was determined using an EGTA-calmagite manual method (Biomérieux kit,


Update 3:

Phosphorus was determined using an ammonium molybdate–iron sulphate manual method (Biomérieux kit, France).

Urea was determined using an urease method (Beckman, model Astra 4).

Creatinine was determined using the Jaffé method (kinetic, Beckman Astra).

Update 4:

The urinary solutes (calcium, magnesium, phosphorus, and urea) were measured in relation to creatinine (ratio).

1 Answer

  • 迷你
    Lv 7
    1 decade ago
    Favorite Answer




    可問題 [2-7]。我們發現值得學習晝夜節律尿變量,目的是建立

    晝夜參考值在青春期男孩。因此,我們審查了24 h尿排泄的一套常規


    9個健康的青春期(唐納第一階段)的男孩年齡 10.8 ± 0.11





    喝的水與 1時 59分每天汽水。父母的同意,兒童的同意之前,獲得進入研究。那個研究批准了審查委員會的研究所和演出協議的標準和倫理生物節律研究[8]。

    研究對象分別於週末在春天,之後類為 24小時,在同一地點(在家中,第一作者)在法國巴黎。受試者須與在床上

    roomlights關閉 from21:00 ħ ± 30分鐘至07:00 ħ ± 30分鐘,1


    在07:30 ħ ± 30分鐘,12:00 ħ ± 30分和20時 00 ħ ± 30分鐘。

    為了規範實驗條件的問候姿勢和身體活動,休息約 30分鐘的兒童在白天


    共收集尿液voidings在連續 9 3 - H的時期。




    鈣是用一張 cresolphthalein方法(生物梅里埃包,法國)。







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