Melatonin attenuates 17 beta-trenbolone induced insomnia-like phenotype and movement deficiency in zebrafish
CHEMOSPHERE
Authors: Mi, Ping; Gao, Qian; Feng, Ze-Yang; Zhang, Jing-Wen; Zhao, Xin; Chen, Dong-Yan; Feng, Xi-Zeng
Abstract
17 beta-trenbolone (17 beta-TBOH) is one of the dominant metabolites of trenbolone acetate, which is widely applied in beef cattle operations around the globe. The effects of environmental concentrations of 17 beta-trenbolone on the early development of zebrafish embryos have received very little attention. Melatonin could regulate sleep-wake cycle and plays a protective role in various adverse conditions. Here, environmentally realistic concentrations of 17 beta-trenbolone (1 ng/L, 10 ng/L, 50 ng/L) has been exposure to zebrafish embryos at 2 h postfertilization (hpf). The results showed that 10 ng/L and 50 ng/L 17 beta-trenbolone disturbed the distribution of caudal primary motoneurons and downregulated expression of motoneuron development related genes along with locomotion decreasing. While melatonin could recover the detrimental effects caused by 17 beta-trenbolone. Interestingly, 17 beta-trenbolone exposure increased waking activity and decreased rest even in a low dose (1 ng/L). Moreover, it upregulated hypocretin/orexin (Hcrt) signaling which promotes wakefulness. Melatonin restored the insomnia-like alternation induced by 17 beta-trenbolone exposure. Collectively, we conclude that 17 beta-trenbolone disturbed motoneuron development and altered sleep/wake behavior, while melatonin could alleviate the deleterious influence on motoneuron development and recover the circadian rhythm. (C) 2020 Elsevier Ltd. All rights reserved.
Hormone Discharges from a Midwest Tile-Drained Agroecosystem Receiving Animal Wastes
ENVIRONMENTAL SCIENCE & TECHNOLOGY
Authors: Gall, Heather E.; Sassman, Stephen A.; Lee, Linda S.; Jafvert, Chad T.
Abstract
Manure is increasingly being viewed as a threat to aquatic ecosystems due to the introduction of natural and synthetic hormones from land application to agricultural fields. In the Midwestern United States, where most agricultural fields are tile-drained, there is little known about hormone release from fields receiving animal wastes. To this end, seven sampling stations (four in subsurface tile drains and three in the receiving ditch network) were installed at a Midwest farm where various types of animal wastes (beef, dairy, and poultry lagoon effluent, dairy solids, and subsurface injection of swine manure) are applied to agricultural fields. Water flow was continuously monitored and samples were collected for hormone analysis during storm events and baseline flow for a 15 month study period. The compounds analyzed included the natural hormones 17 alpha- and 17 beta-estradiol, estrone, estriol, testosterone, and androstenedione and the synthetic androgens 17 alpha- and 17 beta-trenbolone and trendione. Hormones were detected in at least 64% of the samples collected at each station, with estrone being detected the most frequently and estriol the least. Testosterone and androstendione were detected more frequently than synthetic androgens, which were detected in fewer than 15% of samples. Hormone concentrations in subsurface tile drains increased during effluent irrigation and storm events. Hormones also appeared to persist over the winter, with increased concentrations coinciding with early thaws and snowmelt from fields amended with manure solids. The highest concentration of synthetic androgens (168 ng/L) observed coincided with a snowmelt. The highest concentrations of hormones in the ditch waters (87 ng/L for total estrogens and 52 ng/L for natural androgens) were observed in June, which coincides with the early life stage development period of many aquatic species in the Midwest.