In Vivo Testing System for Determining the Estrogenic Activity of Endocrine-Disrupting Chemicals(EDCs) in Goldfish (Carassius auratus).

The intensive use of pesticides has led to their increasing presence in water, soil, and agricultural products. Mounting evidence indicates that some pesticides may be endocrine disrupting chemicals (EDCs), being therefore harmful for the human health and the environment. In this study, three pesticides, glyphosate, thiacloprid, and imidacloprid, were tested for their ability to interfere with estrogen biosynthesis and/or signaling, to evaluate their potential action as EDCs. Among the tested compounds, only glyphosate inhibited aromatase activity (up to 30%) via a non-competitive inhibition or a mixed inhibition mechanism depending on the concentration applied. Then, the ability of the three pesticides to induce an estrogenic activity was tested in MELN cells. When compared to 17β-estradiol, thiacloprid and imidacloprid induced an estrogenic activity at the highest concentrations tested with a relative potency of 5.4 × 10−10 and 3.7 × 10−9, respectively. Molecular dynamics and docking simulations predicted the potential binding sites and the binding mode of the three pesticides on the structure of the two key targets, providing a rational for their mechanism as EDCs. The results demonstrate that the three pesticides are potential EDCs as glyphosate acts as an aromatase inhibitor, whereas imidacloprid and thiacloprid can interfere with estrogen induced signaling.

Download Full-text

In vivo anthelmintic activity of Dryopteris crassirhizoma, Kochia scoparia, and Polygala tenuifolia against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus)

Parasitology Research ◽

10.1007/s00436-011-2592-0 ◽

2011 ◽

Vol 110 (3) ◽

pp. 1085-1090 ◽

Cited By ~ 35

Author(s):

Cheng Lu ◽

Hong-Yu Zhang ◽

Jie Ji ◽

Gao-Xue Wang

Keyword(s):

Carassius Auratus ◽

Anthelmintic Activity ◽

Kochia Scoparia ◽

Goldfish Carassius Auratus ◽

Polygala Tenuifolia

Download Full-text

In-vivo evaluation of dopamine receptor-mediated inhibition of gonadotrophin secretion from the pituitary gland of the goldfish, Carassius auratus

Journal of Endocrinology ◽

10.1677/joe.0.1140449 ◽

1987 ◽

Vol 114 (3) ◽

pp. 449-458 ◽

Cited By ~ 68

Author(s):

R. J. Omeljaniuk ◽

S. H. Shih ◽

R. E. Peter

Keyword(s):

Dopamine Receptor ◽

Carassius Auratus ◽

Time Course ◽

Dopamine Antagonists ◽

Serum Concentrations ◽

In Vivo Evaluation ◽

Goldfish Carassius Auratus ◽

Dopamine Receptor Antagonists ◽

The Brain

ABSTRACT Dopamine acts directly on the pituitary to modulate gonadotrophin (GtH) secretion in goldfish (Carassius auratus). In the light of this important role for dopamine in the regulation of goldfish reproduction, this investigation was designed to evaluate the receptor specificity of this dopamine inhibition and to describe the use of domperidone, a specific dopamine D2-receptor antagonist, in the manipulation of pituitary function in goldfish. To investigate the specificity of dopamine inhibition of GtH secretion, selected dopamine receptor antagonists were injected i.p. to block dopamine receptors thereby increasing GtH secretion as reflected by increased serum concentrations of GtH. Serum GtH levels were significantly increased by the active stereoisomer (−)-sulpiride in a dose-related fashion; (+)-sulpiride had no effect. Comparison of dopamine antagonists at low doses indicated that only domperidone and pimozide caused significant increases in serum concentrations of GtH. Dopamine antagonists potentiated the action of a gonadotrophin-releasing hormone analogue (GnRH-A) with an order of potency of domperidone = pimozide > metoclopramide = fluphenazine. [3H]Domperidone, injected i.p. with unlabelled domperidone, entered the blood and achieved maximum concentrations 12 h after injection, but did not accumulate in the brain in appreciable amounts. Gonadal 3H radioactivity was usually equal to or in excess of blood radioactivity, while [3H]domperidone was highly concentrated in the pituitary in a time-dependent fashion, with maximal accumulation occurring 24 h after injection. The time-course of pituitary accumulation of [3H]domperidone correlated well with the temporal increase in serum GtH levels in response to i.p. injected domperidone or domperidone plus an analogue of LHRH. Domperidone increased serum concentrations of GtH in a dose-related fashion; an analogue of salmon GnRH (sGnRH-A) increased the sensitivity and magnitude of the serum GtH response to domperidone. Serum concentrations of GtH were increased by sGnRH-A in a dose-related fashion; a low dose of domperidone substantially increased the sensitivity of the serum GtH response to sGnRH-A. These results indicate that dopamine inhibits GtH secretion from the goldfish pituitary by acting through a specific mechanism mediated by a dopamine D2 receptor. Domperidone increased serum concentrations of GtH, potentiated the action of gonadotrophin-releasing hormones and did not pass into the brain after i.p. injection into goldfish. The data also suggest that dopamine and GnRH, although acting through different receptors, influence the effect of each other on GtH release. J. Endocr. (1987) 114, 449–458

Download Full-text

Assessment and Molecular Actions of Endocrine-Disrupting Chemicals That Interfere with Estrogen Receptor Pathways

International Journal of Endocrinology ◽

10.1155/2013/501851 ◽

2013 ◽

Vol 2013 ◽

pp. 1-14 ◽

Cited By ~ 31

Author(s):

Gwenneg Kerdivel ◽

Denis Habauzit ◽

Farzad Pakdel

Keyword(s):

Synergistic Effects ◽

Animal Health ◽

Endocrine Disrupting Chemicals ◽

Estrogen Signaling ◽

Synthetic Chemicals ◽

Endocrine Disrupting ◽

And Function ◽

Analytical Tools

In all vertebrate species, estrogens play a crucial role in the development, growth, and function of reproductive and nonreproductive tissues. A large number of natural or synthetic chemicals present in the environment and diet can interfere with estrogen signaling; these chemicals are called endocrine disrupting chemicals (EDCs) or xenoestrogens. Some of these compounds have been shown to induce adverse effects on human and animal health, and some compounds are suspected to contribute to diverse disease development. Because xenoestrogens have varying sources and structures and could act in additive or synergistic effects when combined, they have multiple mechanisms of action. Consequently, an important panel ofin vivoandin vitrobioassays and chemical analytical tools was used to screen, evaluate, and characterize the potential impacts of these compounds on humans and animals. In this paper, we discuss different molecular actions of some of the major xenoestrogens found in food or the environment, and we summarize the current models used to evaluate environmental estrogens.

Download Full-text