In cattle fattening, the illicit use of growth promoters (GPs) represents a major problem. The synthetic corticosteroid dexamethasone (DEX) is the GP mostly used, alone or in combination with other steroids or beta-agonists. Recently, GPs were shown to disrupt some cattle cytochromes P450 (CYPs) at the post-transcriptional level; therefore, the effects of two illicit protocols containing DEX (alone or together with 17beta-estradiol, 17betaE) upon main cattle liver drug metabolizing enzymes (DMEs) mRNAs and related transcription factors were investigated by quantitative real time RT-PCR. Eleven genes, out of the 18 considered, were significantly modulated by GPs. Corticosteroid-responsive genes did not respond univocally, whereas retinoic X receptor alpha (RXRalpha) and estrogen receptor alpha (ERalpha) were upregulated depending on the illicit protocol used. Nowadays, an increasing interest has been noticed toward the detection of biomarkers of response (BMRs) to be used in the screening of GPs misuse in cattle farming. In the present study, CYP2B6-like, CYP2E1, glutathione S-transferase A1- and sulfotransferase A1-like (GSTA1- and SULT1A1-like) mRNAs were significantly modulated regardless of the GP, the illicit protocol, and the animal breed, representing promising BMRs. The usefulness of these BMRs needs to be characterized more in depth.
Fecal glucocorticoid measurement is an important noninvasive tool to monitor animal health. A radioimmunoassay (RIA) method was developed to measure fecal cortisol in bottlenose dolphins under human care. The method was used to measure baseline hormone levels and evaluate the adrenal response to environmental challenges in a small number of individual dolphins. The method was validated by precision and accuracy tests and by comparison with liquid chromatography‐mass spectrometry (LC‐MS). The parallelism test suggested few matrix interferences. The assay showed a good degree of precision within assay (CV = 5.4%) and between assays (CV = 4.1%). The RIA significantly correlated with the LC‐MS method (r = 0.838, P < 0.01). The recovery test and the comparison between RIA and LC‐MS suggested that the RIA slightly underestimates fecal cortisol concentrations, although the degree of accuracy was good. This study established that bottlenose dolphins excrete appreciable amounts of fecal cortisol (healthy subjects: 0.2–9.5 ng/g). Therefore, chronic HPA axis activation may be monitored in fecal samples by immunoassays after validating a suitable extraction protocol. The RIA could discriminate conditions of stimulation (pregnancy, parturition, isolation, transportation) and inhibition (diazepam administration) of the HPA axis and may, therefore, be useful for monitoring dolphin well‐being.
An innovative technology (Physiomimic Technology) has been applied to amino acids (AAs) formulated for patients with phenylketonuria, with the objective of masking AA taste and odor and prolonging AA release in the gut, allowing a physiological absorption. This technology entails that the AAs are processed with functional additives that are able to modify their release and their organoleptic features. Two prototypes, obtained using sodium alginate þ ethylcellulose (engP-1) or sodium alginate þ ethylcellulose þ glyceryl dibehenate (engP-2), have been tested for AA prolonged release versus the same AAs (n-engP) without the application of the Physiomimic Technology. In vitro tests indicated that the technology is able to prolong the release of the engineered AAs versus the free compounds. A crossover in vivo kinetic study in pigs showed reduced peak concentrations (C max ) and, as expected, similar areas under the concentration/time curve (up to 5 hours) for the engineered products versus the free AAs. Significantly lower C max values (P < .01) were attained for essential AAs, large neutral AAs, and branched-chain AAs, indicating that the technology is able to reduce the typical absorption peak of free AAs. Taste and odor masking has been obtained as a consequence of the AA coating. The Physiomimic Technology, applied to free AAs, provided AA mixes with improved organoleptic features and with modified AA kinetics sustaining a more physiological AA absorption.
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