Prednisolone and prednisone neo-formation in bovine urine after sampling

Abstract

The rise in the frequency of detecting prednisolone in bovine urine from northern Italy has come into focus of attention in recent years. The possibility that neo-formation of prednisolone or that prednisone may occur in urine after collection of samples was therefore investigated. Cow urine collected for official routine controls in Lombardy containing more than 80 ng/ml cortisol, and prednisolone and prednisone below the decision limit (CCa) of the method (0.4 and 0.5 ng/ml, respectively) was used. The C 1-2 dehydrogenation of naturally present cortisol and cortisone was checked by incubating urine, both contaminated and uncontaminated with faeces, at 378C and by collecting samples at 0, 1, 2, 4, 6 and 24 h. The influence of Helix pomatia juice was also investigated in order to determine whether deconjugation could influence the reliability of the results. All samples were analysed by HPLC-MS 3 for the presence of cortisol, cortisone, prednisolone and prednisone in negative electrospray ionisation mode, utilising the consecutive reaction monitoring of product ions derived from the formate molecular adduct ([M1HCOO] -). The observed neo-formation of prednisolone shows that inappropriate temperatures in sample storage and processing can result in an incorrect accusation of non-compliance. The faecal contamination of urine, performed with the aim to mimic a collection conducted without the necessary care, moreover, evoked a high increase in prednisolone concentration in two out of seven animals. Moreover, H. pomatia juice had no significant effect on the prednisolone concentration, indicating that this corticosteroid is present in its free form in cow urine.

Study on cortisol, cortisone and prednisolone presence in urine of Chianina cattle breed

“…To some extent, this disagrees with the results shown by Arioli et al. (), who found a significant increase in CL concentration after enzymatic deconjugation. However, with regard to PL, Arioli et al.…”

Presence of endogenous prednisolone in human urine

“…Some studies show that a problem in finding of prednisolone in human, equine and bovine urine exists: this corticosteroid could in fact be the product of a microbiological dehydrogenation of cortisol after the collection of urine samples [8][9][10][11], and endogenous metabolic pathways could also be involved in bovine [12] and equine [13] animals. The analogies between the anabolic steroid boldenone (17b-hydroxy-1,4-androstadiene-3-one) and the glucocorticosteroid prednisolone have to be underlined: both steroids have a C1-C2 double bond; cortisol is released by the adrenal gland in response to stimulation by adrenocorticotropic hormone (ACTH); also androstenedione (4-androsten-3,17-dione; AED), the direct precursor of testosterone (17b-hydroxy-4-androsten-3-one) can be released by adrenals in response to the same stimulation [14]; and AED differs from the precursor of boldenone, androstadienedione (1,4-androstadiene-3,17-dione; ADD), in the same way that cortisol differs from prednisolone, i.e.…”

The presence of prednisolone in complementary feedstuffs for bovine husbandry

“…In these pseudo‐endogenous substances, prednisolone must be mentioned. This corticosteroid was demonstrated to be produced by cattle under stress conditions; additionally, it was found in 612 out of 780 racehorse urine samples at concentrations around 1 ng mL −1 , in all urine samples of 34 untreated human volunteers of both genders and, finally, possible ex vivo neo‐formation in human urine and in bovine urine and faeces was demonstrated. Besides its endogenous origin, it was recently suggested that exogenous prednisolone administrated in bovines, could influence the metabolism of some natural corticosteroids …”