Serotonin-1B receptor activity and expression modulate the aggression-stimulating effects of adolescent anabolic steroid exposure in hamsters.

Repeated high dose (5.0 mg/kg) anabolic-androgenic steroid (AAS) exposure during adolescence stimulates offensive aggression in male Syrian hamsters. These studies examined whether AAS-induced aggression was regulated by the activity of serotonin (5HT) type-1B receptors and correlated with altered 5HT1B expression. AAS-treated hamsters were tested for offensive aggression following the administration of the 5HT1B agonist anpirtoline (0.125-0.5 mg/kg). Anpirtoline dose-dependently reduced select components of the AAS-induced aggressive response, with significant reductions observed at 0.25 mg/kg. Aggressive, AAS-treated hamsters showed significant decreases in the area covered by 5HT1B-containing neuronal puncta and increases in the number of 5HT1B-containing neuronal somata in select brain regions implicated in aggression control. Together, these data support a role for site-specific alterations in 5HT1B signaling and expression in adolescent AAS-induced aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Plasticity in anterior hypothalamic vasopressin correlates with aggression during anabolic-androgenic steroid withdrawal in hamsters.

In hamsters, adolescent anabolic-androgenic steroid (AAS) exposure facilitates offensive aggression, in part by altering the development and activity of anterior hypothalamic arginine vasopressin (AH-AVP). This study assessed whether these effects were lasting by examining aggression and AH-AVP during AAS withdrawal. Adolescent hamsters administered AAS were tested as adults for aggression at 1, 4, 11, 18, or 25 days of withdrawal, sacrificed the following day, and examined for AH-AVP afferent innervation using immunohistochemistry. Through Day 12 of withdrawal, aggression and AVP were significantly higher in AAS-treated hamsters than in controls. These differences were no longer observable by Day 19 of withdrawal, at which point the behavior and neurobiology of AAS-treated hamsters reverted to that observed in controls. These data indicate that adolescent AAS exposure has short-term, reversible effects on both aggression and AH-AVP, correlating AH-AVP with the aggressive/nonaggressive behavioral phenotype during AAS withdrawal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Residues of medroxyprogesterone acetate detected in sows at a slaughterhouse,Madagascar

In Madagascar, little information about drug residues in animal products is available. However, recently, official veterinary services were informed about the misuse of human injectable contraceptives in pig farms as an alternative for chirurgical castration of adult sows before culling. We investigated pigs (n = 80) slaughtered in 7 Malagasy abattoirs and raised in 8 of the 22 Malagasy regions (1) to confirm the contamination of carcasses by anabolic hormones by using LC-MS/MS, (2) to identify the substances of concern and (3) to explore the consumers’ exposure to hormone residues. Medroxyprogesterone acetate was the only synthetic hormone detected in kidney fat. Samples positive with medroxyprogesterone acetate were observed in 66.7% of the districts investigated and in 87.5% of the surveyed regions, confirming its large misuse in livestock. Public awareness campaigns and control improvement among the animal production sector and among the Malagasy public health sector are therefore urgent.     

Presence and metabolism of the anabolic steroid boldenone in various animal species: a review

The review summarizes current knowledge on the possible illegal use of the anabolic steroid boldenone. The presence of boldenone and metabolites in different animal species and the possibility of the occurrence of endogenous boldenone and metabolites is assessed, as are the methods of analysis used for detection. Different laboratories in the European Union have examined the occurrence of boldenone and its metabolites. The results were discussed at different meetings of a European Commission DG-SANCO Working Party and summarized in an expert report. The situation of the different laboratories at this time is also covered herein. The overall conclusion of the Working Party was that there was a necessity for further research to distinguish between naturally occurring and illegally used boldenone forms. The confirmation of the presence of boldenone metabolites (free and conjugated forms) in certain matrices of animals is proposed as a marker for the illegal treatment with boldenone.     

浅析热拌冷铺沥青混合料的强度形成机理

介绍了热拌冷铺沥青混合料技术的应用及优越性，通过试验分析了冷铺沥青混合料的组成特点与强度形成机理，论证了冷铺沥青混合料的强度与矿粉用量、粘聚力、骨料的摩擦角的关系。     

Effects of Methoxyisoflavone, Ecdysterone, and Sulfo-Polysaccharide Supplementation on Training Adaptations in Resistance-Trained Males

Purpose  

Methoxyisoflavone (M), 20-hydroxyecdysone (E), and sulfo-polysaccharide (CSP3) have been marketed to athletes as dietary supplements that can increase strength and muscle mass during resistance-training. However, little is known about their potential ergogenic value. The purpose of this study was to determine whether these supplements affect training adaptations and/or markers of muscle anabolism/catabolism in resistance-trained athletes.     

Detection of endogenous steroid abuse in cattle: results from population studies in the UK

The use of steroids as growth-promoting agents in food production is banned under European Union legislation. Detecting the abuse of testosterone, nandrolone, boldenone, oestradiol and progesterone is complicated by the fact that these steroids are known to be endogenous in certain situations. In this study, the concentrations of characteristic metabolites of each of these steroids were quantified in populations of untreated steers and heifers. Steroid concentration population data were then used by a statistical model (the Chebyshev inequality) to produce threshold concentrations for screening and confirming the abuse of these steroids in steer and non-pregnant heifer urine. In addition to thresholds based on testing one animal (a ‘1 out of 1’ approach), new methods based on testing multiple animals from a herd (a ‘y out of n’ approach) allowed threshold concentrations to be significantly reduced and hence false compliances to be minimised. In the majority of cases, the suggested thresholds were found to be capable of confirming the abuse of endogenous steroids in steers and heifers. In the case of oestradiol abuse in the female, however, confirmation based on a threshold is not possible and alternative methods such as gas chromatography-combustion-isotope ratio mass spectrometry are required. In addition to the steer and heifer populations, a small number of pregnant animals were also tested, yielding insights into the biosynthetic pathways of some of the steroids.     

Phytosterol consumption and the anabolic steroid boldenone in humans: A hypothesis piloted

The presence of the anabolic steroid boldenone in animals has become a research topic as its occurrence is proposed to be a marker for illegal hormone administration. However, boldenone can also be formed from β-sitosterol, a phytosterol present in animal feed, as well as from endogenous sources. The observations in animals together with the increased consumption of phytosterol-enriched foods in the Western population led the authors to the hypothesis that consumption of phytosterol-enriched foods might possibly lead to increased boldenone levels in humans. The authors performed a pilot study among female volunteers (n = 10) to investigate whether boldenone concentrations in urine were detectable after consumption of 25 g day^-1 of phytosterol-enriched margarines for 1 week. Urine samples were collected at days 0, 3 or 4, and 7. Urine of a sitosterolemia (a rare autosomal recessively inherited lipid metabolic disorder) patient was collected as a positive control case. No traces of boldenone were detected in either the volunteers or in the patient. In conclusion, there is no evidence of formation of boldenone in women after consumption of the recommended amount of phytosterol-enriched margarines.     

Natural sex steroids and their xenobiotic analogs in animal production: Growth,carcass quality,pharmacokinetics, metabolism,mode of action,residues, methods,and epidemiology

Natural and xenobiotic compounds having sex‐related actions have long been used for growth promotion and various changes in carcass quality in meat animals. The first compounds used were synthetic estrogens; however, later on a whole battery of compounds having androgenic, and progestogenic actions have also been involved. In surveying the effects of these compounds in meat‐producing animals, it became clear that these drugs increase the growth rate of the treated animals and bring about changes in the carcass that are generally characterized by lower fat content and more lean mass. Extensive studies undertaken in various countries, including the European Economic Community (EEC), have shown that if used according to good husbandry practices, the meat from treated animals does not have excessive amounts of residues compared with the endogenous amount of steroid production in the animals in question and also in human beings. The banning of these compounds in the European community brought a new phenomenon of illegal or black market cocktails. These mixtures of anabolic steroids are injected into the body of the animals rather than implanted in the ears, which is the normal practice in countries where they have not yet been banned. Several screening and confirmatory methods are now available for monitoring programs. However, these programs need excessive resources in terms of manpower, funds, and proper legislation, which in underdeveloped countries is questionable, particularly in the absence of strong scientific evidence for the exercise.