Circadian Rhythms of Serum and Urinary Estrogens in Pregnancy1

Townsley, John D.; Dubin, Norman H.; Grannis, George F.; Gartman, Linda J.; Crystle, C.Deans

doi:10.1210/jcem-36-2-289

Cited by 54 publications

(17 citation statements)

References 1 publication

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“…However, it should be noted that these authors report a coefficient of variation of 22% using the method. Furthermore, they did not run sam- pies in duplicate nor did they study each subject for more than one day (7). The data do not preclude the existence of a diurnal variation in the synthesis of estriol in pregnancy.…”

Section: Resultsmentioning

confidence: 99%

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On the Lack of Periodicity in Plasma Estriol in Human Pregnancy

Levitz

Slyper

Selinger

1974

The Journal of Clinical Endocrinology & Metabolism

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Our method for the assay of total plasma estriol in human pregnancy has been scaled down and modified to accommodate 0.2 ml samples. The method was applied to the evaluation of diurnal rhythms in 7 subjects who were studied at 5 regular intervals on two successive days. Three subjects exhibited little fluctuation over the 48-hr period. The other 4 subjects showed occasional wide fluctuations but in no case did the pattern repeat on the second day. The results contradict 2 previous studies, one emanating from this laboratory, in which circadian rhythms were reported. (J Clin Endocrinol Metab 38: 698, 1974)

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Section: Resultsmentioning

confidence: 99%

“…There was no consistency in the other seven studies (6). On the other hand, Townsley et al (7), studying 22 subjects at 4-hr intervals reported a diurnal variation with peaks at 1200 and 1600 hr and a nadir at 2400 hr. This discrepancy with our previous report prompted a reinvestigation, the results of which are reported here.…”

mentioning

confidence: 91%

On the Lack of Periodicity in Plasma Estriol in Human Pregnancy

Levitz

Slyper

Selinger

1974

The Journal of Clinical Endocrinology & Metabolism

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“…Even so, the constancy of the daily serum oestriol is only a little better than the urine oestrogen output (table III), daily differences of which arise from spasmodic changes in renal clearance (Dickey et al, 1966). Earlier studies on plasma oestriol (Macourt et al, 1971;Masson and Wilson, 1972;Townsley et al, 1973), which were confined to a testing period of 24 hours, revealed no significant diurnal variation; Townsley et al (1973) reported an unconvincing mean diurnal fluctuation of about ± 10%, the lowest levels being at 20.00 hours and the highest at 12 noon. This is not in agreement with our findings.…”

Section: Discussionmentioning

confidence: 98%

A simple radioimmunoassay for serum beta-oestriol in pregnancy.

Nicklin¹,

Hewitt²,

Watson³

1976

J Clin Pathol

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Most clinical laboratories offer determination of the 'total oestrogen' output on a timed urine specimen as a test of fetal function. These assays can conveniently be automated. However, they have a number of disadvantages, namely, the inconvenience of collection timing, the 12-or 24-hour delay, uncertainties due to failure to empty the bladder, and occasional interference from drug metabolites and glucose. An alternative approach is to measure the plasma oestriol level, and an original radioimmunoassay method which is fast enough to allow the reporting of results on the same day has now been developed. The results with this procedure suggest that it may with advantage be substituted for the urine 'oestriol' assay in the assessment of fetal function.Method ANTISERUM Antisera were raised in rabbits to conjugates of oestriol-6-o-carboxymethyl oxime and various mammalian albumins. A conjugate of rabbit albumin produced high-titre antibody with high specificity for oestriol. This antiserum (1-0 ml) was used at a dilution of 1 in 10 000 in carbonate/bicarbonate buffer (0 05 M, pH 9-6) to coat polystyrene tubes (Sarstedt 10 x 55 mm) with a minimum contact time of 24 hours at 4°C according to the method of Catt and Tregear (1967).When required for the assay, each tube is aspirated and treated twice with 1 ml phosphate buffered saline (0-04 mol/l phosphate, 0-6 % NaCl pH 7 4) then with 10 ml of a similar phosphate buffered saline but containing 01 0. bovine albumin. TRACERThe tracer is prepared from oestriol-6-o-carboxymethyl oxime BSA (Steraloids, Croydon) and 125I sodium (Radiochemical Centre, Amersham) by the

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“…A lack of diurnal variation has also been reported for plasma unconjugated oestradiol-17,8 (Tulchinsky and Korenman, 1971) and unconjugated oestriol ) and for plasma total oestriol (Masson and Wilson, 1972). In contrast to the general consensus, Townsley et al (1973a) detected a significant diurnal rhythm in both plasma unconjugated oestradiol-17,8 and total oestriol in a carefully constructed experiment on seven samples taken at four-hourly intervals from each of 22 women. The oestrogen levels were maximum at 12.00-h and minimum at 24.00-h.…”

Section: Oestrogens In Peripheral Plasmamentioning

confidence: 89%