Bioconcentration and endocrine disruption effects of diazepam in channel catfish, Ictalurus punctatus

Autor: Carmen L. Overturf, Duane B. Huggett, M.D. Overturf
Rok vydání: 2016
Předmět:
Male
0301 basic medicine
Physiology
Health
Toxicology and Mutagenesis
medicine.medical_treatment
Aquaculture
010501 environmental sciences
Pharmacology
Toxicology
01 natural sciences
Biochemistry
Random Allocation
Testis
Tissue Distribution
Toxicity Tests
Chronic
Ictaluridae
Sex Characteristics
biology
Gene Expression Regulation
Developmental
General Medicine
Toxicokinetics
Liver
Ictalurus
Female
medicine.drug
Catfish
Fish Proteins
medicine.medical_specialty
3-Hydroxysteroid Dehydrogenases
medicine.drug_class
03 medical and health sciences
Internal medicine
medicine
Animals
Cholesterol Side-Chain Cleavage Enzyme
GABA Modulators
Muscle
Skeletal
0105 earth and related environmental sciences
Benzodiazepine
Diazepam
Cholesterol side-chain cleavage enzyme
Ovary
Cell Biology
biology.organism_classification
Drug Residues
Steroid hormone
030104 developmental biology
Endocrinology
Water Pollutants
Chemical
Hormone
Zdroj: Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology. :46-52
ISSN: 1532-0456
Popis: Recently, the detection of pharmaceuticals in surface waters has increased worldwide. Pharmaceuticals are typically found in the environment at concentrations well below therapeutic levels in humans; however, their mechanisms of action may be largely unknown in non-target organisms, such as teleost species. Thus, chronic exposure to these types of compounds warrants further investigation. The goal of this study was to examine the potential for diazepam, a model benzodiazepine drug, to bioconcentrate in tissues of channel catfish and to examine its ability to interact with the endocrine system through modulation of steroid hormones and/or steroidogenic genes. To investigate the bioconcentration potential of diazepam, channel catfish (Ictalurus punctatus) were exposed to 1 ng/mL diazepam for seven days, followed by clean water for another seven days, using an abbreviated OECD 305 Fish Bioconcentration Test study design. This concentration of diazepam is well below environmentally relevant concentrations of diazepam (ng/L). To evaluate steroidogenic effects, fish were exposed to 1 ng/mL diazepam for seven days only. Steroid hormone concentrations were analyzed for various tissues, as well as expression of selected steroidogenic genes. Calculated bioconcentration factors for diazepam were well below regulatory threshold values in all tissues analyzed. No changes in steroid hormone concentration were detected in any tissue analyzed; however, the steroidogenic gene cytochrome P450 side chain cleavage (P450scc) was significantly down-regulated at day 5 and 3β-hydroxy steroid dehydrogenase (3β-HSD) was significantly down-regulated at day 7 in the gonad. These results indicate that although diazepam does not significantly bioconcentrate, low-level chronic exposure to diazepam may have the potential to interact with endocrine function by altering gene expression.
Databáze: OpenAIRE
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