Back to Search Start Over

Nonylphenol affects gonadotropin levels in the pituitary gland and plasma of female rainbow trout.

Authors :
Harris CA
Santos EM
Janbakhsh A
Pottinger TG
Tyler CR
Sumpter JP
Source :
Environmental science & technology [Environ Sci Technol] 2001 Jul 15; Vol. 35 (14), pp. 2909-16.
Publication Year :
2001

Abstract

Female rainbow trout (Oncorhynchus mykiss) were exposed to 4-nonylphenol (NP) at (mean measured) concentrations of 0.7, 8.3, and 85.6 micrograms/L for 18 weeks, during early ovarian development. Fish were sampled sublethally every six weeks, and terminal samples were taken at 18 weeks. NP induced an estrogenic effect (the synthesis of vitellogenin) at concentrations of 8.3 and 85.6 micrograms/L. An effect on gonadotropin synthesis and secretion was also observed. Plasma follicle stimulating hormone (FSH) levels and FSH gene expression in the pituitary were the most sensitive endpoints assessed, being reduced at the lowest dose employed (0.7 microgram NP/L). Pituitary gland luteinizing hormone (LH) content was significantly lower in fish exposed to 85.6 micrograms NP/L, and LH gene expression was suppressed in fish exposed to 8.3 and 85.6 micrograms NP/L. In contrast, plasma LH concentration increased in these fish, but by a very minor absolute amount, and returned to control levels by the final sampling time. Gonadal development ceased in the fish exposed to 85.6 micrograms NP/L, and steroidogenesis in these fish was also markedly inhibited. Although the mechanisms underlying these responses are unknown, this study demonstrates that NP has adverse effects on pituitary function that can result in inhibition of ovarian development.

Details

Language :
English
ISSN :
0013-936X
Volume :
35
Issue :
14
Database :
MEDLINE
Journal :
Environmental science & technology
Publication Type :
Academic Journal
Accession number :
11478242
Full Text :
https://doi.org/10.1021/es0002619