Efectes de l'exposició al n-butilparabèn en el sistema reproductor masculí i l'estrès oxidatiu en testicles de rates joves

Identificador:  TDX:3026

Handle: https://hdl.handle.net/20.500.11797/TDX3026

Autors:  Schreiber Bru, Elga

Resum:
Parabens (PBs) are exogenous chemical compounds for humans that are used in a wide range of products as a preservatives. Personal care products and cosmetics are the main sources of human exposure to PBs. Progressively, there has been growing social interest about PBs due to their estrogenic effects as well as a possible relationship with breast cancer or with dermal allergies. Currently, there are several studies that show reproductive system alterations due to PBs. It has also been observed how PBs can generate oxidative stress (OE). However, studies focusing on the OE in the reproductive system and PBs are limited. Due to the growing social concern about the PBs' uses, new studies are required, especially at the subcutaneous level in males. The main objective of this doctoral thesis is to determine if n-butylparaben (n-ButP) can generate toxic effects on the reproductive system of young male rats treated subcutaneously during a complete spermatogenic cycle. In addition, another aim is to determine if n-ButP can generate OE in testes. Young male rats were treated subcutaneously with three doses of n-ButP: 150, 300, and 600 mg/kg/d. Two control groups were also added: with vehicle (peanut oil) and without vehicle. The main results of the study showed that n-ButP caused a significant increase in the abnormal morphology of sperm, as well as alterations in histopathology of the testes and the seminal vesicle. Regarding OE, an increase was observed due to the vehicle, except in the highest dose. A possible antioxidant effect due to n-ButP and its metabolites was suggested in the highest dose. The general conclusion of this doctoral thesis is that n-ButP acts as an endocrine disruptor in young male rats, causing changes in sperm level and histopathology of the testes and the seminal vesicle, changes that may be related to infertility. However, n-ButP does not cause OE on testes, which is generated by the vehicle's exposure. Moreover, n-ButP and its metabolites generate an antioxidant effect in the highest dose.