Propiconazole inhibits steroidogenesis and reproduction in the fathead minnow (Pimephales promelas).
نویسندگان
چکیده
Conazoles are designed to inhibit cytochrome P450 (CYP) 14α-demethylase, an enzyme key to fungal cell wall formation. In vertebrates, conazoles may inhibit other CYPs, potentially disrupting processes like sex steroid synthesis. Propiconazole is a current-use pesticide that is among the first chemicals being tested in the U.S. Environmental Protection Agency endocrine disruptor screening program. Fathead minnows (Pimephales promelas) were exposed to 0, 5, 50, 500, or 1000 µg propiconazole/l in a 21-day study that evaluated apical reproductive endpoints (fecundity, fertility, hatch); measures of endocrine function and steroid synthesis, such as cholesterol, vitellogenin (VTG), and sex steroid (testosterone [T], 17β-estradiol [E2]) concentrations in the plasma; and changes in gonadal expression of steroidogenic genes. Plasma E2 and VTG concentrations in females were reduced by exposure to propiconazole, and egg production was decreased in the 500 and 1000 µg/l treatment groups. These in vivo effects coincided with inhibition of E2 synthesis by ovary explants exposed to propiconazole in vitro. We also observed a compensatory response in females exposed to propiconazole, manifested as increased gonad weight and upregulation of genes coding for key steriodogenic proteins, including CYP19 (aromatase), CYP17 (hydroxylase/lyase), CYP11A (cholesterol side-chain-cleavage), and steroidogenic acute regulatory protein. Other than an increase in relative testis weight, effects on endocrine function in males were less pronounced than in females. This study provides important data relative to the potential endocrine activity of propiconazole in fish and, more generally, to the further delineation of pathways for the reproductive effects of steroid synthesis inhibitors in fish.
منابع مشابه
EFFECTS OF SERTRALINE EXPOSURE ON FATHEAD MINNOW (Pimephales promelas) STEROIDOGENESIS Dennis R. Carty Thesis Prepared for the Degree of MASTER OF SCIENCE UNIVERSITY OF NORTH TEXAS December 2014 Carty, Dennis R. Effects of Sertraline Exposure on Fathead Minnow (Pimephales
متن کامل
Chronic Toxicity of Di-n-butyl and Di-n-octyl Phthalate to Daphnia Magna and the Fathead Minnow
The toxicities of di-n-butyl phthalate (DBP) and di-n-octyl phthalate (DOP) were assessed by measuring the effect of exposure to these compounds on the fecundity of Daphnia magna and on the hatching and survival of the early life stages of the fathead minnow Pimephales promelas. For D. magna, exposure to 1.8 mg/L DBP or 1.0 mg/L DOP caused a significant reduction in reproduction. Doses of 0.56 ...
متن کاملModeling impacts on populations: fathead minnow (Pimephales promelas) exposure to the endocrine disruptor 17beta-trenbolone as a case study.
Evaluation of population-level impacts is critical to credible ecological risk assessments. In this study, a predictive model was developed to translate changes in fecundity of the fathead minnow (Pimephales promelas) in a short-term laboratory toxicity test to alterations in population growth rate. The model uniquely combines a Leslie population projection matrix and the logistic equation. App...
متن کاملEvaluation of the aromatase inhibitor fadrozole in a short-term reproduction assay with the fathead minnow (Pimephales promelas).
Cytochrome P450 aromatase (CYP19) is a key enzyme in vertebrate steroidogenesis, catalyzing the conversion of C19 androgens to C18 estrogens such as beta-estradiol (E2). The objective of this study was to assess effects of the CYP19 inhibitor fadrozole on fathead minnow (Pimephales promelas) reproductive endocrinology and physiology in a short-term reproduction assay proposed for identifying sp...
متن کاملThe Toxicity of the Hydrolysis and Breakdown Products of Malathion to the Fathead Minnow (pimephales Promelas, Rafinesque)*
Abstract Malathion undergoes hydrolysis in aqueous solutions; the products derived from the reaction are dependent upon the pH of the medium. It was the purpose of this investigation to evaluate the toxicity of the products of malathion hydrolysis in the fathead minnow, Pimephales promelas. The studies were conducted by toxicity bioassays of 96 hr duration and continuous exposure tests of 14 da...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Toxicological sciences : an official journal of the Society of Toxicology
دوره 132 2 شماره
صفحات -
تاریخ انتشار 2013