Effect of Gestational Exposure to Nonylphenol on the Development and Fertility of Mouse Offspring

Abstract

Abstract. Nonylphenol (NP), a kind of environmental chemical, is thought to imitate endogenous hormones, inhibit the actions of hormones, and induce reproductive abnormalities. A number of experimental animals, usually rats, have been used to evaluate the potential reproductive toxicity of NP. However, the findings of previous studies were contradictory in some cases. Therefore, we used ICR mice as a biomodel for in utero study of NP. After mating, 8-to 12-week-old females were assigned to four groups (n=8) for subcutaneous injections from day 5 to 20 of gestation. Group I animals received corn oil alone as a control, while the mice of groups II, III and IV received NP at concentrations of 1/1000, 1/100 and 1/10 of the LD50, respectively. A dose-dependent decrease was observed in terminal body weights of males of the F1 generation; however, a very small negative effect was only found in the females of the NP1/10 group. No significant effect was found on the liver weights of both sexes. The weights of the testis and epididymis were slightly decreased in the NP1/ 10 group. The NP1/100 treatment increased ovary weight considerably. The uterus weight tended to be increased in the NP treatment groups; however, there were large variations. The gestational exposure of the groups had no significant effect on the rate of pregnancy (94.4-100%) and the number of fetuses per litter (13.6-14.3 males, 12.3-13.7 females) compared with the control group. However, the overall mortality of fetuses/embryos was increased considerably in the NP1/100 (male: 13.9%) and NP1/10 (female: 9.8%) groups. These results suggest that exposure to NP in utero possibly affects the body weight and some reproductive organ weights, but does not influence the potential fertility of the F1 generation.

Male-mediated F1 effects in mice exposed to nonylphenol or to a combination of X-rays and nonylphenol

“…Other investigators have reported that in rodents, reduced testes weight implied diminished sperm concentration in the epididymides (de Jager et al, 1999b;Chapin et al, 1999;Han et al, 2004;Kimura et al, 2006). In male mice treated with 42.50 mg/kg NP for 35 consecutive days, reduced testes and epididymides weights, diminished sperm count, and mortality were observed (El-Dakdoky and Helal, 2007).…”

Combined action of X-rays and nonylphenol on mouse sperm

“…Nonylphenol (NP) is the final degradation product of alkylphenol polyethoxylates, which are widely used in the preparation of lubricating oil additives, resins, plasticizers, surface-active agents, detergents, paints, cosmetics and other formulated products [4,6]. It is also widely used in the manufacture of nonionic surfactants, polymer stabilizers, and antioxidants [7]. NP has been found in polyvinyl chloride, which is used in the food processing and packaging industry and contaminates the water flowing through polyvinyl chloride (PVC) pipes [6].…”

“…NP possesses oestrogenic properties and has been shown to disrupt the male reproductive system of fish, reptiles and mammals [9][10][11]. The residual nature of nonylphenol and its lipophilic character leads to its accumulation in the lipids of living organisms [7,12,13]. Neonatal exposure of rats to NP had an effect on the weight of the reproductive organs and delayed testes descent, whereas exposure of adult rats affects spermatogenesis [14,15].…”

The Association between Nonylphenols and Sexual Hormones Levels among Pregnant Women: A Cohort Study in Taiwan

“…Kimura et al (2006) suggest that NP exposure in utero possibly affected fetal body weight and some reproductive organ weights [56]. A dose-dependent effect of NP on decreased epididymal weight of male rats was reported [57].…”