Critical study of common conditions of storage of glucocorticoids and catecholamines in 24-h urine collected during resting and exercising conditions.
BACKGROUND
Except immediate freezing of the samples, no practical method has been validated for preservation of glucocorticoids and catecholamines in 24-h urine collection. Furthermore, the influence of urine storage at bladder temperature during periods of different lengths and the effect of prior exercise on preservation of these hormones in the bladder have not been investigated until now.


METHODS
Ten healthy volunteers collected their urine both after a resting and after an exercise session. Urine was aliquoted into tubes which were stored during 24 h in the presence or in the absence of preservatives and at different temperatures. Two samples were stored either 3 or 9 h at 37 degrees C (bladder temperature) without additive.


CONCLUSIONS
When collecting 24-h urine samples for glucocorticoids determination, sample can be stored at room temperature during the 24-h collection period without compromising glucocorticoids preservation. When collecting 24-h urine samples for catecholamines determination, samples have to be chilled without preservative during the whole of the collection period. If the samples have to be stored at room temperature, HCl should be used. Moreover, we report for the first time that catecholamines can be degraded in the bladder and therefore that subjects should urinate every 3 h during either a resting or an exercising day.
Gouarne
C
C
Laboratory of Neurogenetic and Stress, INSERM-INRA-University of Bordeaux II, Institute François Magendie, Camille St Saëns Street, 33077 Bordeaux Cedex, France. gouarne@pop.bordeaux.inserm.fr
Foury
A
A
Duclos
M
M
D000293:Adolescent; D000328:Adult; D002395:Catecholamines / Q000652:urine*; D003348:Cortisone / Q000652:urine; D004492:Edetic Acid; D004837:Epinephrine / Q000652:urine; D015444:Exercise; D005260:Female; D005938:Glucocorticoids / Q000652:urine*; D006801:Humans; D006851:Hydrochloric Acid; D006854:Hydrocortisone / Q000652:urine; D006863:Hydrogen-Ion Concentration; D008297:Male; D009638:Norepinephrine / Q000652:urine; D011309:Preservation, Biological; D013048:Specimen Handling; D013696:Temperature; D013997:Time Factors
D002395:Catecholamines; D005938:Glucocorticoids; D004492:Edetic Acid; D006851:Hydrochloric Acid; D003348:Cortisone; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine